Boston Cream Pie

Classic Boston Cream Pie With Chocolate Ganache

There’s something so satisfying about baking this Boston cream pie from scratch. I love the creaminess of the filling and softness of the cake layers, covered with rich chocolate ganache. There’s truly no other dessert like it.

I make my Boston cream pie filling the traditional way, by beating the eggs and sugar before pouring in hot milk and butter to make a rich, creamy custard. I’ve seen recipes that use instant pudding as a shortcut for this step, but if you ask me, it doesn’t compare to the taste of homemade.

Then there’s the cake layer! It’s an airy, soft sponge similar to my vanilla cake roll. The cake can be a little thin in classic Boston cream pie, so I made my cake layers a bit thicker to better balance the pastry cream. I think it turned out pretty delicious, and I hope you’ll think so, too!

Ingredient Notes

Scroll to the printable recipe card for the full recipe with amounts. For now, here’s a look at the key ingredients.

• Egg Yolks – It’s easier to separate the yolks from the egg whites while the eggs are cold from the fridge. I’ll sometimes save the whites to make a batch of Swiss meringue buttercream or a white cake.
• Cornstarch – Thickens the filling without affecting the flavor.
• Whole Milk – Lower-fat options will yield a less creamy filling, so stick with whole milk.
• Vanilla – Pure vanilla extract is essential for a subtle, authentic flavor. Avoid imitation.
• Butter – I recommend unsalted butter for the pastry cream and cake.
• Flour – See how to measure flour correctly using a digital kitchen scale or the spoon-and-level method.
• Oil – I make this Boston cream pie with oil for an ultra-moist texture. I use canola oil, but vegetable oil can also be used. 
• Chocolate Ganache – I make homemade chocolate ganache from heavy cream and semi-sweet chocolate, and add light corn syrup to give it a high-gloss finish.

Preparing the Pastry Cream for Boston Cream Pie

I always begin with the homemade custard. The filling in this Boston cream pie is similar to my original pastry cream. I increased the sugar and added an extra egg yolk while using less milk to make the filling a bit sturdier. Tempering the eggs is important here, so they don’t scramble in the heat.

1. Beat the egg yolks. Start by beating the egg yolks, sugar, and cornstarch until they’re pale and thick. In the meantime, heat the milk on the stovetop just until it starts to simmer (not boil). 
2. Temper the eggs. Now, add about half of the hot milk to the egg yolks, whisking to temper them, and then whisk the eggs into the saucepan with the rest of the milk. Keep whisking until the mixture thickens and starts to bubble.
3. Take the pastry cream off the heat and strain it. Straining prevents any lumps and bits of cooked egg from finding their way into the finished filling. Next, stir in vanilla extract and cubed butter until the butter has melted. Store the pastry cream in a shallow container. I press a sheet of plastic wrap directly against the pastry cream so a skin doesn’t form while it cools. Afterward, move it to the fridge to chill completely before assembling the pie.

How to Make Boston Cream Pie From Scratch

The steps to prepare the filling and bake the cake layers take time, but this isn’t a difficult dessert. If you’re new to assembling layer cakes, you can bake the cake layers in round pans as directed, and assemble your Boston cream pie in a springform pan afterward. This way, everything stacks evenly, and you can simply release the sides after it chills. Easy!

Make the Cake Layers

I usually bake the cake layers while the pastry cream chills in the fridge.

• Make the cake batter. Whisk the dry ingredients in a bowl. In a separate bowl, beat the eggs and sugar for 5-7 minutes, until they’re pale and bubbly. Then, fold the dry ingredients into the beaten egg mixture, followed by the oil and vanilla.
• Heat the milk and butter. Meanwhile, melt butter with milk in a microwave-safe bowl. The milk should hit around 190-195°F on an instant-read thermometer. Stream the hot milk into your cake batter, stirring until it’s fully added. Stir gently so you don’t deflate the air bubbles you worked into the batter in the previous step!

• Bake the cakes. Divide the batter between two greased and floured cake pans. I usually weigh the batter with a kitchen scale, so I know my cakes are even. The cakes go into a 350ºF oven for 22-25 minutes. Test them for doneness using a toothpick. Rest the cakes in the pans, and remove them after 10 minutes to let them cool completely.

Assemble

Lastly, with your cake and pastry cream prepared and cooled, it’s time to layer the Boston cream pie. Ensure that your custard is completely cool before you assemble the pie, or the filling may run out the sides.

• Make the chocolate ganache. When you’re ready to assemble, melt chocolate with heavy cream and corn syrup in the microwave in minute intervals, stirring until smooth. Set the ganache aside.

• Stack the layers. Starting with the first cooled cake layer, spoon chilled pastry cream on top. Spread that evenly, then place the second cake on top of the cream. 
• Finish and refrigerate. Pour and spread the ganache over the cake. This Boston cream pie should go into the fridge for at least 1 hour before you slice it, so the chocolate can set.

Frequently Asked Questions

How to Store

Keep the cake chilled because of the cream filling. It will stay fresh when covered or stored in an airtight container in the fridge for up to 3 days. If you cover the cake with plastic wrap, place some toothpicks around the top before covering it to keep the plastic wrap from touching the ganache. 

More Bakery-Style Dessert Recipes

• Banana Cream Pie
• Coconut Custard Cake
• Coconut Cream Pie
• Lemon Meringue Pie
• French Silk Pie