Boston Cream Cake

Make the Cake

1. Prep the pans. Heat oven to 350°F. Grease two 9-inch round cake pans, line bottoms with parchment, then lightly grease the parchment. Dust with flour if you are nervous about sticking.

2. Mix dry ingredients. In a bowl, whisk together flour, baking powder, and salt.

3. Cream butter and sugar. In a large bowl (or stand mixer), beat butter and sugar until light and fluffy, about 3 minutes. Add eggs one at a time, then mix in vanilla.

4. Finish the batter. Add dry ingredients in two additions, alternating with milk, mixing just until combined. Do not overmix.

5. Bake. Divide batter between pans and smooth tops. Bake 22 to 27 minutes, but start checking at 20 minutes, until a toothpick comes out clean and the tops spring back when lightly pressed. Optional precision cue: the center should read about 200 to 205°F.

   

6. Cool completely. Cool in pans 10 minutes, then turn out onto racks to cool all the way. Warm cake plus pastry cream equals sliding.

Make the Pastry Cream

1. Warm the milk. In a medium saucepan, heat milk with 1/4 cup of the sugar until steaming with small bubbles around the edges, not boiling.

2. Whisk yolks. In a bowl, whisk yolks, cornstarch, salt, and remaining 1/4 cup sugar until smooth and pale.

3. Temper. Slowly whisk in about half the hot milk into the yolk mixture, then pour everything back into the saucepan.

4. Cook until thick. Cook over medium heat, whisking constantly, until it bubbles. Once bubbling, keep whisking for 60 to 90 seconds until thick and glossy. It should leave thick tracks from the whisk.

5. Finish and chill. Remove from heat, whisk in butter and vanilla. Strain if needed. Press plastic wrap directly onto the surface and chill until cold and set, about 2 hours.

   

Assemble

1. Level if needed. If your cakes domed, trim tops with a serrated knife so they stack neatly.

2. Fill. Place one cake layer on a serving plate. Spread all the chilled pastry cream evenly to the edges. Top with the second layer, cut-side down if you trimmed.

3. Chill. Refrigerate the filled cake for 30 minutes so it firms up before ganache.

Make the Ganache and Glaze

1. Heat cream. Place chopped chocolate in a bowl. Heat cream until it just begins to simmer, then pour over chocolate. Let sit 2 minutes.

2. Stir smooth. Stir from the center outward until glossy. Try not to whisk aggressively since it can add bubbles and dull the finish. Add butter and salt, stir again.

3. Cool slightly, then pour. Let ganache cool 5 to 10 minutes until it is thick but pourable and ribbons off a spoon. (If you like numbers: about 86 to 90°F.) Pour onto the center of the cake and gently nudge it toward the edges with an offset spatula, letting a little drip naturally.

   

4. Set and slice. Chill 20 to 30 minutes to set the top for clean slices. Serve slightly cool or let slices sit at room temperature 10 minutes for maximum custard creaminess.