Boston Cream Pie Recipe

Prep

Preheat the oven to 350°F (175°C). Line a 9x2-inch round cake pan or for cupcakes, line a standard 12-cup muffin tin with liners and preheat oven to 350°F (175°C). If making cupcakes, this recipe yields about 10–12 cupcakes depending on fill.

Whisk together the dry ingredients: in a medium bowl, sift or whisk 1.5 cups all-purpose flour, 1 cup granulated sugar, 1.5 tsp baking powder and 1/4 tsp salt until well combined.

Combine wet ingredients: in a separate bowl, whisk 2 large eggs with 1/2 cup whole milk, 1/4 cup melted cooled unsalted butter and 1 tsp vanilla extract until smooth.

Make the batter: pour the wet into the dry and fold gently until just combined. Do not overmix; a few small lumps are fine. For cupcakes, fill each liner about 2/3 full (roughly 3 tbsp batter per cupcake). For a 9-inch cake pan, pour batter into the prepared pan and smooth the top.

Bake: for cupcakes, bake 16–20 minutes or until a toothpick inserted into the center comes out clean. For a 9-inch pan, bake 22–28 minutes. Remove from oven and cool in the pan for 10 minutes, then transfer to a wire rack to cool completely before filling.

Infuse the milk: in a medium saucepan, combine 2 cups whole milk and the seeds scraped from 1 vanilla bean plus the pod (or 1 tbsp vanilla extract). Heat over medium until steaming and just about to simmer; do not boil. Remove from heat and let sit for 5 minutes if using a vanilla bean, then discard the pod.

Whisk yolks and dry: in a bowl, whisk 4 large egg yolks with 3/4 cup granulated sugar until pale and slightly thickened. Whisk in 1/4 cup cornstarch until smooth and fully incorporated.

Temper and thicken: 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. Cook over medium heat, whisking constantly, until the mixture thickens and comes to a gentle boil—about 2–4 minutes. Continue cooking for 30–60 seconds to activate the cornstarch.

Finish pastry cream: remove from heat and whisk in 2 tbsp unsalted butter and 1/8 tsp salt until butter is melted and the cream is smooth. Transfer the pastry cream to a shallow bowl, press plastic wrap directly onto the surface to prevent a skin, and chill in the refrigerator until fully cold, at least 2 hours (or 30–45 minutes in a shallow container for cupcakes).

Warm the cream: place 1/2 cup heavy cream in a small saucepan and bring just to a simmer over medium heat. Remove from heat.

Make ganache: pour the hot cream over 4 oz finely chopped semi-sweet chocolate in a heatproof bowl. Let sit 1 minute, then whisk until smooth and glossy. Whisk in 1 tbsp unsalted butter, if using, for extra shine. Allow the glaze to cool slightly until thickened but still pourable (about 5–10 minutes).

For cupcakes: core each cooled cupcake by removing a small cone from the center (save the tops). Spoon or pipe about 1 to 1.5 tablespoons of chilled pastry cream into each cavity; replace the cake top or leave a small well.

For cake: if making a 9-inch cake, slice the cooled cake horizontally into two layers. Spread an even layer (about 1 to 1 1/2 cups) of chilled pastry cream on the bottom layer, then place the top layer back on.

Top with glaze: place filled cupcakes on a wire rack set over a tray or spoon the glaze over the top of the filled cupcakes, letting it drip down the sides slightly. For a cake, pour the chocolate glaze over the top and spread to the edges to coat evenly. If glaze is too thin, chill briefly until it firms slightly and then pour; if too thick, gently warm to loosen.

Finish and serve: let the glaze set at room temperature for 15–30 minutes or refrigerate briefly to speed setting. Optionally dust with powdered sugar or scatter sprinkles/toasted nuts. Store assembled Boston Cream cupcakes/cake in the refrigerator for up to 3 days; bring to cool-room temperature before serving for best flavor.