These tangy and sweet Lemon Blueberry Cupcakes are irresistibly soft and fluffy, and filled with a homemade blueberry sauce. They’re the best summer dessert topped with beautiful swirls of vanilla and blueberry frosting!
This post is sponsored by the Oregon Blueberry Growers. All opinions are my own.
Homemade Lemon Cupcakes with Blueberry Filling
Nothing says summer more than fresh Oregon Blueberries, whether you’re enjoying them with ice cream, pairing them with a slice of cake, or simply enjoying them with a bowl of whipped cream, there’s no shortage of ideas to serve them with.
Today I am whipping up a batch of homemade lemon cupcakes with a juicy blueberry filling made with Oregon Blueberries. I even saved a little bit of the filling to pair together with my vanilla frosting and turned it into a beautiful blueberry and vanilla frosting swirl. It turned out absolutely gorgeous!
I have partnered with the Oregon Blueberry Growers again this year. We look forward to berry season every summer. Oregon is one of the top-producing states for blueberry harvests, and there are so many great u-pick farms to choose from. We always pick more than we need and freeze the rest to enjoy through the fall and winter.
If you find yourself with extra berries on hand, you can whip up a batch of blueberry bread or mini blueberry pies.
Now let’s break down the different elements of this cupcake, and I am going to teach you how to make a stunning Lemon Blueberry Cupcake.
Ingredient Notes and Substitutions
Between the cupcakes, filling, and frosting there’s a bit of work involved, but the payoff is well worth it. Besides the standard cupcake ingredients like flour, sugar, eggs etc, there are a few special ingredients you’ll need. The full recipe card is at the bottom of this post. Be sure to pay attention to the temperature of the ingredients specified in the recipe.
- Fresh lemon: These are both zested and juiced for the cupcake and a touch of lemon juice for the frosting. If you don’t have a zester, here are a few more handy ways to do it.
- Lemon extract: Used to help amplify the flavor in the cupcakes. Substitute with vanilla extract as needed.
- Sour cream: This is the secret to soft, tender, and moist cupcakes. Substitute with plain or Greek yogurt.
- Buttermilk: Tangy buttermilk helps maintain the texture and flavor of the cupcakes. If you don’t have any on hand, you can make your own with this handy homemade version.
- Fresh blueberries: This homemade filling uses fresh Oregon blueberries cooked down with some sugar to release the juices. Some of the sauce is also used in the frosting for even more blueberry flavor.
- Corn starch: Used in the blueberry sauce. All-purpose flour can also be used.
- Unsalted butter: I always make my buttercream with unsalted butter so that I can add the salt to taste. Salted butter can also be used, but in that case, omit the added salt.
How to Make Lemon Blueberry Cupcakes
Make the Cupcakes
- Mix the wet ingredients. First, combine granulated sugar with the eggs, oil, and lemon extract and beat until combined. Mix in the sour cream along with the lemon zest.
- Mix the dry ingredients and combine. In a separate bowl, whisk together the dry ingredients then add half to the wet ingredients with the lemon juice. Mix on low speed until the flour is combined. Then add the remaining dry ingredients with the buttermilk and mix on low speed until thoroughly combined.
- Fill and bake. Divide the batter evenly between your cupcake liners, about ⅔ full. I prefer using a large cookie scoop. Bake the cupcakes at 350ºF for 15 minutes, or until a toothpick inserted into the middle of a cupcake comes out clean. Allow the cupcakes to cool completely before filling and frosting.
Make the Filling
Once the blueberry sauce is prepared, you’ll need to separate out ¼ cup of the sauce to puree for the frosting. If you prefer a less chunky blueberry filling to place inside the cupcakes, you can puree the entire batch of sauce once it’s cooled.
Step 1: Combine and Cook. Stir together the blueberries and sugar and transfer to a large saucepan with 2 tablespoons of water. Cook over medium-high heat until the mixture starts to bubble and release the juices, stirring often to prevent burning. As the blueberries break down, combine 1 tablespoon water with the cornstarch and stir to dissolve; add to the blueberries and mix to combine.
Step 2: Simmer. Turn down the heat and let simmer to allow the blueberries to soften and further cook down. Cook and stir often until sauce starts to thicken; around 10-15 minutes. Then remove from the heat and cool completely. You can refrigerate the sauce as needed. It will further thicken as it cools.
Step 3: Puree for frosting. Separate ¼ cup of the blueberry sauce for the frosting. Puree in a food processor until it reaches a smooth consistency. Set aside.
Make the Frosting
You’ll see that the base of my vanilla buttercream starts with cold butter. This is not a mistake! It’s my secret to the perfect consistency. The mixer will break down and beat the butter to soften it. It’s important that the vanilla and blueberry buttercream has a similar consistency so that it holds its shape.
Beat the butter. Begin by cutting your cold butter into cubes (about 1 tablespoon in size), then whip it for several minutes to get it whipped, fluffy, and easily spreadable.
Combine. Next, mix in 2 cups of the powdered sugar, followed by the vanilla, and beat until it’s a smooth consistency. Next, add 3 more cups of powdered sugar with the lemon juice and salt. You’ll want to beat this for a couple of minutes at a high speed until it’s completely smooth and fluffy.
Add the blueberry puree. Puree the ¼ cup of blueberry sauce if you haven’t done so already. Separate out half of the vanilla buttercream and set aside. To the mixing bowl add 2 tablespoons of sauce and mix to combine. If the frosting seems thin or runny, add an additional ½ cup of powdered sugar. Additional puree can be added to taste, but you may need to add more powdered sugar to match the consistency of the vanilla buttercream.
How to Fill and Assemble The Frosting
I just love how the three components of this cupcake come together, but I especially love the swirled buttercream. If you’re looking for a little less work, consider just going straight to a blueberry buttercream instead of separating it in half.
Prepare the Piping Bag
To assemble a piping bag with 2 different frostings, you can do it a couple of different ways. Most importantly, you don’t want to overfill the bags, as this makes it difficult to handle. Before you begin, browse through my tutorial for using piping bags which goes over some of these tips in greater detail.
Note that in either method I described below, I find it easier to fill a separate piping bag with each frosting first, then combine them. You’ll go through several piping bags, but it does make it a lot less messy.
How to Fill The Piping Bags
Double bag method: This method utilizes one piping bag fitted with a tip, and another bag filled with the frosting. This is great because once you need to refill, it’s easy to remove the bag of frosting and replace it with another prefilled bag.
To fill the bag of frosting, fold in half over a glass exposing the bag and pipe each of the frostings down each side of the bag and squeeze the frosting down the bag to remove excess air.
Plastic wrap: Another method for filling a piping bag is using plastic wrap. Each frosting can either be piped or spread onto a piece of plastic wrap, which is then tightly rolled with the tip cut off and dropped into the piping bag fitted with the tip. For a visual tutorial, see the post for these rainbow cupcakes.
Fill and Assemble
Scoop out the center of the cupcake. Use a cupcake corer, a knife or a melon baller to remove the center of the cupcake about halfway down. Make sure that you don’t go too far down into the cupcake. Save those centers to the side, because you will put them back on top of the filling.
Fill the cupcakes. Use a spoon to fill the centers of the cupcake with the blueberry filling, and then place the cupcake tops back on. You can remove a little bit of the crumbs if needed. Gently press into the filling to give it a “seal”.
Add the frosting. Once the buttercream is prepared, add the frosting. I used a large closed star tip, Ateco 849. With this buttercream you can use any of the large piping tips, you can see more options for decorating cupcakes here.
Preparation and Storage
Prepare ahead:
The sauce can be prepared 48 hours ahead of time and kept in the refrigerator in an airtight container.
The cupcakes are best within the first day or two but can be prepared ahead and kept at room temperature in an airtight container.
The frosting can be prepared up to 7 days in advance and kept in the refrigerator in an airtight container. Bring back to room temperature and re-whip in the mixer before using. In this case, add the blueberry puree once it’s re-whipped.
Storing
Once frosted, cupcakes can be stored in an airtight container at room temperature for 24 hours. If it’s hot or humid, then I recommend refrigerating in an airtight container. Cupcakes will stay fresh in the refrigerator for 3-4 days. These are best served at room temperature.
Freezing
I don’t recommend freezing frosted and assembled cupcakes. Instead, you can freeze the separate components, the cupcakes, filling or frosting. Use airtight, freezer-safe containers. Allow the ingredients to come back to room temperature before assembling. The frosting should be re-whipped before use, and add the blueberry sauce after the fact.
Lemon Blueberry Cupcakes
- Prep Time: 60 minutes
- Cook Time: 16 minutes
- Total Time: 1 hour 16 minutes
- Yield: 24 Cupcakes
- Category: Cupcakes
- Method: Baked
- Cuisine: American
Description
These tangy and sweet Lemon Blueberry Cupcakes are irresistibly soft and fluffy, and filled with a homemade blueberry sauce. They’re the best summer dessert topped with beautiful swirls of vanilla and blueberry frosting!
Ingredients
For the Cupcakes
- 2 cups (380g) granulated sugar
- 1/2 cup (118ml) vegetable oil
- 3 large eggs, at room temperature
- 2 lemons, zested and juiced
- 1 teaspoon (5ml) lemon extract, or pure vanilla extract
- 1/2 cup (118ml) sour cream, at room temperature
- 2 1/2 cups (350g) all-purpose flour
- 3 teaspoons (11.2g) baking powder
- 1 teaspoon (5g) salt
- 1/4 cup (59ml) lemon juice, (from the zested lemons)
- 1 cup (236ml) buttermilk, at room temperature
For the Blueberry Sauce
- 18 ounces (510g) fresh Oregon blueberries, rinsed.
- ¼ cup (48g) granulated sugar
- 1 tablespoon cornstarch (or AP flour)
- 3 tablespoons (45ml) water, divided
For the Frosting
- 1 1/2 cups (339g) unsalted butter, cold
- 5 ½ cups (715 g) powdered sugar
- 1 teaspoon (5ml) pure vanilla extract
- 1 tablespoon (15ml) fresh lemon juice (or milk)
- ¼ teaspoon salt
- 2–3 tablespoons blueberry puree (made from blueberry sauce)
Instructions
For the Cupcakes:
- Preheat the oven to 350°F. Line cupcake pans with cupcake liners.
- In a large mixing bowl, combine the sugar, vegetable oil, eggs, and lemon extract. Beat on medium speed until the eggs and oil are well incorporated, scrape down the bowl as needed. Next, add the lemon zest and the sour cream and beat until well combined.
- Combine the dry ingredients in a separate bowl. Alternate adding half the dry ingredients followed by half of the liquid ingredients (buttermilk and lemon juice) and mix just until the flour starts to incorporate. Use a spatula to scrape down the sides of the bowl and stir the batter from the bottom to the top to ensure it’s well mixed.
- Using a large cookie scoop, divide the batter evenly, filling each liner 2/3 full. Bake at 350°F for 15-18 minutes. Test the cupcakes for doneness by inserting a toothpick into the center of the cupcake. If the toothpick comes out clean, the cupcakes are done. Cool Completely.
For the Blueberry Sauce:
- In a medium-sized bowl, combine the blueberries and sugar and stir to combine. Transfer to a large saucepan, add 2 tablespoons water, and cook over medium-high heat until the mixture starts to bubble and release the juices, stirring often. As the blueberries break down, combine 1 tablespoon water with the cornstarch and stir to dissolve; add to the blueberries and mix to combine.
- Turn down the heat and let simmer to allow the blueberries to soften and further cook down. Cook until sauce starts to thicken; around 10-15 minutes. Stir often so the bottom does not burn. Remove from the heat and cool completely, refrigerate if necessary. The sauce will further thicken as it cools.
- Separate ¼ cup of the blueberry sauce and puree in a food processor or blender until it reaches a smooth consistency. Set aside.
For the Frosting
- Cut the butter into pieces. Using the paddle attachment, whip the butter for 5-7 minutes, scraping down the bowl occasionally, and beating until the butter looks light in color.
- Add 2 cups of powdered sugar and the vanilla extract and mix on low speed until incorporated, then increase the speed to high, and beat for approximately 60 seconds or until well combined. Scrape down the bowl. Add the remaining 3 cups of powdered sugar, lemon juice, and salt. Beat on low until the ingredients start to mix together. Increase speed to high and beat for another 2-3 minutes until it reaches desired consistency.
- Separate out half of the frosting and set aside in a bowl. To the mixer add 2 tablespoons of blueberry puree and mix to combine. If the frosting seems thin or runny, add an additional ½ cup of powdered sugar. Add additional puree to taste.
To Assemble
- Assemble the piping bag. Fit a large piping bag with a large tip and fill it half full with both vanilla and blueberry frosting (see notes for additional tips).
- Remove the centers using a cupcake corer. Save the tops of the cupcakes to the side.
- Use a spoon to fill the center of each cupcake with the blueberry filling. Gently push the top of the cupcake back on top of the filling and frost.
Notes
Ingredient substitutions:
- Buttermilk: Make a homemade buttermilk using milk with either lemon juice or vinegar.
- Sour cream: Use plain or Greek yogurt.
- Fresh blueberries: Frozen blueberries can be used instead. Additional corn starch may be needed to help thicken.
Storing
Once frosted, cupcakes can be stored in an airtight container at room temperature for 24 hours. If it’s hot or humid, then I recommend refrigerating in an airtight container. Cupcakes will stay fresh in the refrigerator for 3-4 days. These are best served at room temperature.
Prepare ahead:
The sauce can be prepared 48 hours ahead of time and kept in the refrigerator in an airtight container. The cupcakes are best within the first day or two but can be prepared ahead and kept at room temperature in an airtight container. The frosting can be prepared up to 7 days in advance and kept in the refrigerator in an airtight container. Bring back to room temperature and re-whip in the mixer before using. In this case, add the blueberry puree once it’s rewhipped.
Filling the piping bag:
To assemble a piping bag with 2 different frostings, you can do it a couple of different ways. I find it easier to fill piping bags individually and then use those to squeeze the frosting into the third bag fitted with the tip. Alternatively, you can pipe the frosting onto a large piece of plastic wrap, fold it together and drop it into a piping bag. For a visual tutorial, see the post for these rainbow cupcakes.
