Martha Stewart's Boston Cream Pie

Ingredients

• Pastry Cream, see recipe
• 6 tablespoons unsalted butter, plus more for pan
• 1 cup sugar
• 1 1/2 cups all-purpose flour, plus more for pan
• 1 1/2 teaspoons baking powder
• 1/2 teaspoon salt
• 3 large eggs
• 1/2 cup milk
• 1/4 cup heavy cream
• 4 ounces semisweet chocolate, chopped
• 1 teaspoon vanilla extract

Directions

1. Heat the oven to 350 degrees. Butter and flour a 9-inch round cake pan. In a small bowl, whisk the flour, baking powder, and salt together, then put that aside. Add the milk and butter to a small saucepan and place it over very low heat.
2. Using an electric mixer, beat the eggs and sugar on high speed until the mixture is thick, pale, and leaves a visible ribbon for several seconds when you lift the beater, 4 to 5 minutes. Slowly whisk in the dry ingredients, stopping as soon as they’re incorporated.
3. Bring the milk and butter mixture to a boil. Turn the mixer to low speed and pour the hot milk mixture into the batter, mixing only until the batter is smooth. Add the vanilla, mix it in, then pour the batter into the prepared pan and smooth the top.
4. Bake the cake until it is golden and beginning to pull away from the sides of the pan, 35 to 40 minutes. Let it cool in the pan for 10 minutes, then take it out of the pan and set it right side up on a rack to cool.
5. To fill the cake, slide a piece of waxed paper under the rack to keep things tidy. Use a serrated knife to cut the cooled cake in half horizontally, leaving the bottom half on the rack. Spread the bottom half with Pastry Cream, stopping within 1/2 inch of the edge, then carefully set the top half of the cake over the cream.
6. For the chocolate glaze, bring the heavy cream to a boil in a small saucepan. Take the pan off the heat, add the chocolate, and stir until the glaze is smooth.
7. Let the glaze cool to room temperature and thicken a little, about 10 minutes. Once it has thickened, pour it over the filled cake. Use a small metal spatula to guide the glaze out to the edges so it can run down the sides. Let the glaze set, 15 to 20 minutes. Any leftover cake can be loosely covered and refrigerated for up to 2 days.