Classic Boston Cream Pie Recipe (From Scratch)

A close-up view of a slice of Classic Boston Cream Pie sitting on a white dessert plate with a fork resting nearby.

Classic Boston Cream Pie Recipe (From Scratch)

Course: Dessert

Cuisine: American

Prep Time: 20

Cook Time: 40

Rest and chill time: 1

Total Time: 2

Servings:

Calories: 588kcal

Author: Kris Longwell

This quintessential Boston Cream Pie features a light-as-air sponge cake, a rich and silky vanilla custard filling, and a stunningly glossy chocolate ganache. It’s a fail-proof, from-scratch classic that is guaranteed to be the star of any dessert table.

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Equipment

Stand mixer or an electric hand mixer, or both
2 9-inch straight cake pans lined with parchment paper (optional, but helpful)

Ingredients

For the Vanilla Pastry Cream (Custard)

2 cups whole milk
½ cup sugar
¼ cup cornstarch
¼ teaspoon salt
4 large egg yolks
2 tablespoon unsalted butter
2 teaspoon vanilla extract

For the Hot Milk Sponge Cake

1½ cups all-purpose flour
1½ teaspoon baking powder
¼ teaspoon salt
3 large eggs room temperature
1 cup sugar
¾ cup whole milk
6 tablespoon unsalted butter cut into cubes
1 teaspoon vanilla extract

For the Chocolate Ganache

4 oz semi-sweet chocolate 56% cacao, finely chopped
1 tablespoon light corn syrup
½ cup heavy cream

Instructions

Prepare the Vanilla Pastry Cream (Custard)

In a medium saucepan, whisk together the milk and ¼ cup of the sugar. Bring to a slight simmer.
2 cups whole milk, ½ cup sugar
Meanwhile, in a medium-sized bowl (or in the bowl of your stand mixer), whisk the remaining ¼ cup of sugar, cornstarch, and salt. Add the egg yolks and use an electric hand mixer (or your stand mixer with whisk attachment) to whisk until the mixture is pale and slightly thickened, about 3 to 4 minutes.
¼ cup cornstarch, ¼ teaspoon salt, 4 large egg yolks
Temper the egg mixture by slowly pouring about half of the hot milk into it, whisking constantly to prevent scrambling the eggs.
Pour the egg mixture back into the saucepan with the rest of the hot milk, whisking constantly. Continue to whisk and stir until the mixture thickens and begins to bubble on the surface. Remove from the heat and stir in the butter and vanilla.
2 tablespoon unsalted butter, 2 teaspoon vanilla extract
Strain through a fine-mesh sieve into a bowl. Press plastic wrap directly onto the surface of the custard and refrigerate until completely chilled.

Prepare the Hot Milk Sponge Cakes

Preheat your oven to 350°F. Grease and flour 2 9-inch round cake pans. Line with parchment paper and spray with cooking spray (optional, but helpful).
In a medium-sized bowl, whisk the flour, baking powder, and salt together. Set aside.
1½ cups all-purpose flour, 1½ teaspoon baking powder, ¼ teaspoon salt
In a stand mixer (or in a bowl with an electric hand mixer), beat the eggs and sugar on HIGH speed for about 5 minutes until very pale and smooth.
3 large eggs, 1 cup sugar
While beating the eggs, heat the milk and cubed butter in a small saucepan over medium heat until the butter is melted and the milk is just starting to simmer. Stir in the vanilla.
¾ cup whole milk, 6 tablespoon unsalted butter, 1 teaspoon vanilla extract
Turn the mixer to LOW. Alternatively, add the flour mixture and the hot milk mixture, starting with one third of the flour mixture, then half of the milk mixture, another third of the flour, then the rest of the milk, and finally the rest of the flour. Mix until just combined.
Pour into the prepared pans and bake for 15 to 20 minutes, or until an inserted toothpick comes out clean. Place the pans on a baking rack.
Cool in the pans for 10 minutes. Run a sharp knife along the sides of the pan and then gently turn the cakes out onto the wire rack to cool completely.

Prepare the Chocolate Ganache and Assemble the Cake

Place the chopped chocolate and corn syrup into a heatproof bowl or measuring cup.
4 oz semi-sweet chocolate, 1 tablespoon light corn syrup
Heat the heavy cream until it just starts to simmer. Pour the hot cream over the chocolate and let it rest for a few minutes. Stir or whisk until the chocolate is smooth and glossy. Let it rest for only a few minutes to slightly cool (it should still be pourable).
½ cup heavy cream
Meanwhile, place one of the cakes on your serving plate. Stir or whisk the chilled pastry cream (custard) until smooth. Use a spatula to spread the pastry cream evenly over the cake, leaving a ½-inch border at the edge.
Place the second cake on top. Press down very gently so the cream reaches the edges but doesn't spill over. Smooth with a spatula, if desired.
Pour the warm (but not hot) ganache over the center of the cake. Use an offset spatula to gently push it toward the eggs, letting some of it drip slightly down the sides.
Chill for about 30 minutes to allow the ganache to set before slicing.

Video

Notes

NOTE: Watch the video in the recipe card for visual guidance.

Storage: Because of the custard filling, this cake should be stored in the refrigerator. It will stay fresh in an airtight container for up to 3 to 4 days. Freezing is not recommended as the pastry cream texture will break down.
Make-Ahead Tip: You can prepare the pastry cream up to 24 hours in advance. The sponge cake can also be baked a day early; once completely cool, wrap it tightly in plastic wrap and store at room temperature until you are ready to assemble.
Custard Consistency: To ensure your filling doesn't squish out the sides, make sure the pastry cream reaches a full boil (large, slow bubbles) for at least one minute. This "activates" the cornstarch so it sets firmly.
The Perfect Drip: Let your ganache cool for 10–15 minutes before pouring. It should be thick enough to coat a spoon but still fluid; if it’s too hot, it will run off the cake rather than creating those beautiful, thick drips.
Serving: For the best flavor and texture, take the cake out of the fridge about 20 minutes before serving to let the sponge cake soften slightly, but keep it cool enough that the custard remains stable.

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