This Boston cream pie has two layers of moist and tender vanilla sponge cake filled with a silky pastry cream, and it’s finished with a dark chocolate ganache on top.
Prep Time:30 min
Cook Time:30 min
Total Time:1 hour
Method:stovetop & bake
2cups (500ml) whole milk
1/4cup (50g)+ 1/3 cup (65g) granulated sugar,divided
1 large whole egg
2 large egg yolks
1/4cup (30g) cornstarch
2tbsp (28g) unsaltedbutter
1tsp (5ml)vanilla extract
1/2cup (114g) unsalted butter,softened
1/2cup (125ml) vegetable oil
1 1/2cups (300g) granulated sugar
1 1/2cups (375ml) buttermilk, room temperature
3large eggs,room temperature
1tbsp (15ml)vanilla extract
3½cups (440g) all-purpose flour
4tspof baking powder
1/2 cup (125ml) heavy cream
4 oz semi-sweet chocolate chips
In a medium sauce pan, stir together the milk and 1/4 cup sugar. Bring to a simmer on the stovetop over medium heat. In a separate mixing bowl, whisk together egg, egg yolks, cornstarch, and 1/3 cup sugar.
Once the milk has reached a simmer, carefully pour half of the hot milk in a steady stream into the egg mixture, whisking constantly to avoid curdling the eggs. Immediately whisk the egg mixture back into the saucepan.
Return to stovetop and continuing to cook over medium heat while whisk constantly until mixture thickens.
Remove from heat once thickened and stir in butter and vanilla until melted. Pour into a clean mixing bowl and press a sheet of saran wrap directly on top of the surface of the pastry cream to prevent a skin from developing. Cool completely in the refrigerator for at least 4 hours.
Preheat oven to 350F. Grease two 9″ pans and line the bottom with parchment paper.
In a large mixing bowl, use a hand mixer to cream the butter, vegetable oil, and sugar together until light and fluffy. Add in buttermilk, eggs, and vanilla and beat until combined. The mixture will look curdled, but that’s okay. It will come together when you add in the dry ingredients.
Add in flour, baking powder, and salt, and mix until just combined. Divide the batter among the two prepared baking pans.
Bake for 25 – 30 minutes or until a toothpick inserted into the center comes out clean.
Let cool completely before assembling.
In a small sauce pan, bring the heavy cream to a simmer over medium heat. Place your chopped chocolate into a small mixing bowl. Pour hot cream over chocolate and let stand 1 – 2 minutes. Stir with a rubber spatula until smooth. Let stand for 15-30 minutes to thicken the ganache before pouring on top of cake.
Trim cake domes if necessary. Place one of the cakes on a serving plate.
Spread the pastry cream on top. Place the second cake layer on.
Slowly pour the ganache on top, letting it drip down the sides a little.
Chill in the fridge for 1 hour to let the chocolate set, or cover and refrigerate overnight.
You can prepare and assemble this cake a day in advance. Cover and store it in the fridge overnight to let it firm up. This makes it much easier to slice and serve.