Boston Cream Pie Recipe

Prepare and Preheat

Preheat oven to 350°F (175°C). Grease and line the bottom of a 9-inch (23 cm) round springform pan or two 9-inch round cake pans with parchment. If using a single full-size pie format, use a 9-inch or 10-inch round cake pan depending on desired height.

Dry Ingredients

In a medium bowl sift together 1.5 cups all-purpose flour, 1.5 tsp baking powder and 1/4 tsp salt. Set aside.

Cream Butter and Sugar

In a large bowl or stand mixer fitted with a paddle, cream 1/2 cup softened unsalted butter and 1 cup granulated sugar on medium-high until light and fluffy, about 3–4 minutes.

Add Eggs and Vanilla

Add eggs one at a time, mixing well after each addition. Add 2 tsp vanilla extract and mix until incorporated.

Combine Batter

With the mixer on low, add flour mixture in three additions alternating with 1/2 cup whole milk, beginning and ending with flour. Scrape bowl and mix just until combined; do not overmix.

Bake

Pour batter into prepared pan(s) and smooth the top. Bake at 350°F (175°C) for 22–28 minutes (about 25 minutes for a single 9-inch cake) or until a toothpick inserted into the center comes out clean. Cake should spring back when lightly pressed.

Cool

Allow cake to cool in the pan for 10–15 minutes, then run a knife around the edge and turn out onto a wire rack. Peel off parchment and cool completely before slicing horizontally to create two layers for filling (if baked as a single thicker cake).

Heat Milk

In a medium saucepan, heat 3 cups whole milk and 1 tsp vanilla (or split vanilla bean scraped) over medium heat until just steaming — do not boil.

Whisk Yolks

While milk heats, whisk together 6 egg yolks and 3/4 cup granulated sugar in a bowl until pale and slightly thickened. Whisk in 1/2 cup cornstarch and 1/8 tsp salt until smooth and lump-free.

Temper Eggs

Slowly pour about 1/3 of the hot milk into the yolk mixture in a thin stream while whisking constantly to temper the eggs. Then pour the tempered yolk mixture back into the saucepan with the remaining milk, whisking continuously.

Cook Custard

Return saucepan to medium heat and cook, whisking constantly, until the mixture thickens and comes to a gentle boil (about 2–4 minutes). Continue cooking and whisking for an additional 1 minute to fully cook the starch and remove raw flavor.

Finish and Chill

Remove from heat and whisk in 3 tbsp unsalted butter until melted and smooth. Pour pastry cream into a shallow bowl and press plastic wrap directly onto the surface to prevent a skin from forming. Chill until completely cold, at least 2–3 hours (can be made a day ahead).

Heat Cream

Place 1/2 cup heavy cream in a small saucepan and bring just to a simmer (do not boil). Remove from heat.

Make Ganache

Place 8 oz chopped semi-sweet chocolate in a heatproof bowl. Pour the hot cream over the chocolate and let sit for 1–2 minutes to soften. Stir gently until smooth and glossy. Add 2 tbsp unsalted butter and 1 tbsp light corn syrup (optional) and stir until incorporated and shiny. Let the glaze cool slightly so it will thicken enough to coat the cake but still pourable.

Slice Cake

If you baked a single cake, slice horizontally into two even layers using a serrated knife or cake leveler. If you baked two pans, you already have two layers.

Optional Syrup

If using, brush the cut sides of each cake layer lightly with 1/4 cup simple syrup to add moisture and flavor.

Fill

Place the bottom cake layer on a serving plate or springform base. Spoon or pipe the chilled pastry cream onto the bottom layer, spreading evenly to within about 1/2 inch of the edge. Use all of the pastry cream so the top layer sits snugly. Place the top cake layer over the filling, pressing gently to even out.

Chill Before Glazing

Chill the assembled cake in the refrigerator for 20–30 minutes so the filling firms and the cake is easier to glaze.

Glaze

Place the cake on a wire rack set over a sheet pan to catch drips. Pour the slightly cooled chocolate glaze over the center of the cake, using an offset spatula to gently coax glaze to the edges so it drips down the sides and fully covers the top. Smooth to an even layer. If necessary, spoon additional glaze around the edges for full coverage.

Final Chill and Serve

Transfer the glazed cake back to the refrigerator and chill at least 30 minutes to set the glaze and filling. Before serving, you may dust the edges with a light sprinkle of powdered sugar if desired. Slice with a sharp knife dipped in hot water and wiped dry between cuts for clean slices. Serve chilled or at cool room temperature.