Boston Cream Pie

Make pastry cream first. Heat milk in a saucepan until steaming. In a bowl whisk sugar, salt, cornstarch, yolks, and whole egg until smooth.

Slowly whisk about one-third of the hot milk into the egg mixture, then return everything to the saucepan.

Cook over medium heat, whisking constantly, until the pastry cream bubbles and becomes thick, about 2 minutes after it reaches a boil.

Remove from heat, stir in vanilla, transfer to a shallow container, and press plastic wrap directly on the surface. Chill at least 2 hours.

Heat oven to 325°F. Grease and parchment-line two 9-inch round pans.

Beat sugar and eggs until pale, thick, and increased in volume, about 4 minutes. Beat in oil.

Whisk flour, baking powder, and salt. Gently fold into the egg mixture.

Heat milk and butter just until the butter melts and the milk is steaming. Stir in vanilla. Gradually fold the hot milk mixture into the batter.

Divide between pans and bake 30–35 minutes, until golden and a tester comes out clean.

Cool in pans 10 minutes, then turn out and cool completely.

Place one cake layer on a serving plate. Spread the cold pastry cream evenly over it, leaving a small border. Top with the second cake layer.

For the ganache, pour hot cream over chopped chocolate. Let stand 2 minutes, then stir from the center outward until glossy. Stir in vanilla.

Cool ganache until slightly thickened but pourable, then spread over the top so a little drips naturally down the sides. Chill at least 30 minutes before slicing.