Boston Cream Pie

Preheat the oven to 325 degrees. Butter two 9-inch round baking pans, line them with parchment paper, butter and flour the pans, and tap out the excess flour. Set aside.

For the cake, scald the milk and butter in a small saucepan over medium heat (see note). Off the heat, add the vanilla and orange zest, cover the pan, and set aside. In a small bowl, sift together the flour, baking powder, and salt and set aside.

In the bowl of an electric mixer fitted with the paddle attachment, beat the eggs and sugar on medium-high speed for 4 minutes, until thick and light yellow and the mixture falls back on itself in a ribbon. By hand, first whisk in the warm milk mixture and then slowly whisk in the flour mixture. Don’t overmix! Pour the batter evenly into the prepared pans. Bake for 22 to 25 minutes, until a toothpick comes out clean. Allow the cakes to cool in the pans for 15 minutes, then turn them out onto a baking rack, flipping them so the top sides are up. Cool to room temperature.

For the soak, combine the orange juice and sugar in a small (8-inch) sauté pan and heat until the sugar dissolves. Off the heat, add the Grand Marnier and set aside.

For the chocolate glaze, combine the heavy cream, semisweet chocolate chips, bittersweet chocolate, corn syrup, vanilla, and coffee in a heatproof bowl set over a pot of simmering water. Stir occasionally with a wooden spoon, just until the chocolates melt. Remove from the heat and set aside for 25 to 30 minutes, stirring occasionally, until the chocolate is thick enough to fall back on itself in a ribbon.

To assemble, cut both cakes in half horizontally. Place the bottom of one cake on a flat plate, cut side up. Brush it with a third of the soak. Spread a third of the Grand Marnier Pastry Cream on the cake. Place the top of the first cake on top, cut side down, and repeat with the soak and pastry cream. Place the bottom of the second cake on top, cut side up. Repeat with the soak and pastry cream. Place the top of the second cake on top, cut side down. Pour the ganache on the cake, allowing it to drip down the sides. Set aside for one hour, until the chocolate sets. Cut in wedges and serve.

Beat the egg yolks and sugar in the bowl of an electric mixer fitted with the paddle attachment on medium-high speed for 4 minutes, until very thick. Reduce the speed to low and add the cornstarch.

Meanwhile, scald the milk in a medium saucepan. With the mixer on low, slowly pour the hot milk into the egg mixture. Pour the mixture back into the saucepan and cook over medium-low heat for 5 to 7 minutes, stirring constantly with a wooden spoon, until the mixture starts to thicken. When the custard starts to clump on the bottom of the pan, stir constantly with a whisk (don’t beat it!) to keep the custard smooth.

Cook over low heat until the custard is very thick like pudding. If you lift some custard with the whisk, it should fall back onto itself in a ribbon. Off the heat, stir in the butter, heavy cream, Grand Marnier, Cognac, and vanilla. Whisk until smooth and transfer to a bowl. Cool for 15 minutes. Place plastic wrap directly on the custard (not the bowl) and refrigerate until very cold.

NOTES:

To scald milk, heat it just below the boiling point—there will be small bubbles around the edge of the milk. Don’t let it boil!

Don’t refrigerate the assembled cake because beads of condensation will form on the chocolate.

MAKE AHEAD:

Prepare the cakes and pastry cream, wrap well, and refrigerate separately. Prepare the chocolate glaze and assemble an hour before serving.