For the Cake

1. Preheat the oven to 350°F. Grease two 8-inch cake pans with Crisco and dust with flour to help easily release the cake after it is baked. I also line the bottom of the pans with parchment paper to ensure they don’t stick.
2. In a large mixing bowl, combine the sugar, vegetable oil, butter, eggs, egg yolks and vanilla extract. Beat on medium speed until the eggs and oil are well incorporated and the batter is lighter in color, about 2 minutes. Scrape down the bowl as needed. Next mix in the sour cream and beat until well combined.
3. In a separate bowl, combine the remaining dry ingredients. Alternate adding half the dry ingredients and half the buttermilk at a time and mix just until the flour starts to incorporate. Then add remaining dry ingredients and buttermilk and beat until well combined. 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. Mix in the sprinkles by hand.
4. Divide the cake batter evenly between the two 8-inch pans. Bake at 350° F for 25 to 32 minutes. Check the cakes for doneness by inserting a toothpick into the center of the cake. If the toothpick comes out clean, the cake is done. Allow the cake to cool in the pans for 15 minutes. Then gently run a knife around the edges of the cake and flip them out of the pan and onto a rack to cool completely. Once the cake is cooled, you can prepare the ice cream.

Fill and Assemble

1. Allow the ice cream to soften on the counter for 15-20 minutes so it’s spreadable.
2. Cut off the domes on top of the cake layers so they’re relatively flat. Prepare an 8-inch springform pan. If you don’t have a springform pan, use the pan that you baked the cake in. Line the whole pan with plastic wrap, then place the cake board in the bottom of the pan.
3. Place one layer of cake in the bottom of the pan.
4. Spread the ice cream over the cake and spread evenly, and then place the second cake layer inverted on top of the ice cream.
5. Wrap the entire cake with plastic wrap twice and freeze the cake for at least 2 to 4 hours until the ice cream is frozen.

Decorate

1. Prepare a batch of whipped cream. Chill the bowl in the freezer or refrigerator for 5-10 minutes. Beat the heavy whipping cream in the chilled bowl at medium-high speed until soft peaks form. Slowly add the powdered sugar and sprinkles and continue beating at high speed until stiff peaks form. Place the whipped cream in a large piping bag with the tip cut off.

1. To frost the cake, remove it from the pan and pipe it around the outside edge of the cake and on the top. Gently smooth with an angled spatula. Decorate with leftover whipped cream and additional sprinkles.
2. Refreeze for 30-60 minutes before slicing.