Homemade Boston Cream Pie

A slice of Boston cream pie on a light grey plate with fork.

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.

Course Dessert

Cuisine American

Method stovetop & bake

Prep Time 30

Cook Time 30

Total Time 1

Servings servings

Calories 700

Author Lily Ernst

Ingredients

Pastry Cream

2 cups (240ml) whole milk
1/4 cup (50g) granulated sugar
1 large egg
2 large egg yolks
1/4 cup cornstarch
1/3 cup (67g) granulated sugar
2 Tbsp unsalted butter
1 tsp vanilla extract

Cake

1/2 cup salted butter softened
1/2 cup (120ml) vegetable oil
1 & 1/2 cups (300g) granulated sugar
1 & 1/2 cups (360ml) buttermilk room temperature
3 large eggs room temperature
1 Tbsp vanilla extract
3 & 1/2 cups (440g) all-purpose flour
4 tsp baking powder
1/2 tsp salt

Ganache

1 cup (240ml) heavy cream
8 oz dark chocolate roughly chopped

Instructions

Pastry Cream
In a medium sauce pan, stir together the milk and 1/4 cup sugar. Bring to a simmer on the stovetop over medium heat.
2 cups (240ml) whole milk, 1/4 cup (50g) granulated sugar
In a separate mixing bowl, whisk together egg, egg yolks, cornstarch, and 1/3 cup sugar.
1 large egg, 2 large egg yolks, 1/4 cup cornstarch, 1/3 cup (67g) granulated 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.
2 Tbsp unsalted butter, 1 tsp vanilla extract
Cake
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.
1/2 cup salted butter, 1/2 cup (120ml) vegetable oil, 1 & 1/2 cups (300g) granulated sugar
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.
1 & 1/2 cups (360ml) buttermilk, 3 large eggs, 1 Tbsp vanilla extract
Add in flour, baking powder, and salt, and mix until just combined. Divide the batter among the two prepared baking pans.
3 & 1/2 cups (440g) all-purpose flour, 4 tsp baking powder, 1/2 tsp salt
Bake for 25 - 30 minutes or until a toothpick inserted into the center comes out clean.
Let cool completely before assembling.
Ganache
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.
1 cup (240ml) heavy cream, 8 oz dark chocolate
Assembling
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.

Notes

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.

Nutrition