Boston Cream Cake

👨‍🍳 Method

For the Sponge Cake

1. 1
   Preheat the oven to 175°C (345°F).

   ⚙ Preheating the OvenOven

   💡Put things in the oven only once it's reached temperature, after the heating light has gone off: an oven that hasn't reached temperature changes baking times, and the bake burns outside or stays underbaked.
2. 2
   Whip the eggs and the sugar 6–8 minutes, until the mixture is pale, thick and very fluffy.

   ⚙ WhippingBowlHand mixerorStand mixerorWhisk

   💡With whole eggs, all the rise comes from the whipping: whip until the mixture leaves a ribbon on its surface, and fold in the flour gently so the air doesn't escape.
3. 3
   Add the oil, milk and vanilla and mix on low speed, just until they are absorbed.
4. 4
   Sift the flour and baking powder over the top and Fold gently, just until the flour is absorbed.

   ⚙ FoldingSilicone spatulaSifter

   💡Fold with a spatula, in broad strokes from the bottom up, and stop when there are no streaks: vigorous mixing knocks the air out of the foam. Add whipped mixtures in stages: a quarter first, to lighten the mixture.

   💡Fold with a spatula, in broad strokes from the bottom up, and stop when there's no dry flour: vigorous mixing of a batter with flour develops gluten.
5. 5
   Pour into a round pan 24 cm in diameter.

   Round pan
6. 6
   Bake 25 minutes, until a toothpick inserted in the center comes out dry.

   ⚙ BakingOvenRound pan

   💡Check by the cue (until…), not just the clock: every oven bakes a little differently.
7. 7
   Let the cake cool completely.

For the Cream Filling

1. 8
   Heat the milk to just below a boil.

   StovePot
2. 9
   In a bowl, whisk the egg yolks, sugar and starch.

   BowlWhisk
3. 10
   Pour the hot milk in a thin stream into the mixture, whisking constantly.

   ⚙ Tempering eggsWhisk

   💡The hot liquid goes into the eggs slowly while whisking, and only about a third of it in the first batch: that way they warm gradually and don't turn into scrambled eggs.
4. 11
   Return to the pot and cook over medium heat, stirring constantly, until the cream thickens and bubbles in the center, then cook 1–2 more minutes.

   StovePot

   💡Stir nonstop until it bubbles: only then does the starch thicken fully, and the cream won't turn runny later.
5. 12
   Transfer to a bowl, cover with plastic wrap touching the surface of the cream and let cool.

   BowlPlastic wrap

For the Ganache

1. 13
   Finely chop the chocolate and put it in a bowl.

   KnifeCutting boardBowl
2. 14
   Heat the cream until just about to boil and pour over the chocolate. Wait a minute without touching.

   StoveSmall saucepan
3. 15
   Stir gently from the center outward, until you get a smooth, glossy cream.

   💡Stir gently from the center outward: vigorous stirring beats in air, and the ganache loses its shine.
4. 16
   Cut the cooled cake horizontally into two layers.

   Knife
5. 17
   Spread the cream over the bottom layer and place the second layer on top.

   💡Assemble when the cake and the cream are completely cool: warm cream slides out from between the layers and makes the cake soggy.
6. 18
   Pour the ganache over the top and chill 1 hour in the fridge, until the glaze sets.

   Refrigerator