Boston cream pie

Yield: 1 22cm layer cake

Prep Time: 1 hour (plus 3+ hours for chilling pastry cream)

Assembly Time: 10 minutes

Special Equipment: KitchenAid Light & Shadow stand mixer with whisk attachment; 22cm cake pan; pastry spatula

Ingredients:

For the pastry cream:

590ml milk

100g caster sugar

½ tsp vanilla paste (or 1 teaspoon vanilla extract)

5 large egg yolks

3 tbsp plain flour

2 tabsp cornstarch

Pinch of salt

2 tbsp butter

1 tsp bourbon or rum (optional)

For the cake:

6 large eggs

200g sugar

135g flour

2 tbsp butter, melted

For the chocolate ganache:

230g semi-sweet chocolate, finely chopped

240ml heavy cream

¼ cup - ½ cup crushed roasted hazelnuts (or almond slices) to garnish

Prepare pastry cream:

1. Pour the milk and a quarter cup of the sugar into a saucepan, and turn the heat to medium.
2. Whisk gently to combine, and add in the vanilla paste. Whisk again.
3. Allow the mixture to cook without stirring until the milk is steaming and a skin begins to form on the top. Do not boil the milk.
4. In a separate bowl, whisk together the egg yolks and remaining quarter cup of sugar. The yolk mixture is ready when it is slightly thickened and forms ribbons (about 60 seconds).
5. Sift the flour, cornstarch and salt into the yolk mixture. Whisk again until smooth.
6. When the milk is ready, add ⅓ of the hot milk into the yolk mixture whilst whisking constantly.
7. Pour the tempered yolks into the saucepan with the remaining milk, stirring constantly.
8. Increase the heat to medium high and bring to a boil while whisking.
9. Once it starts to bubble, reduce heat to a simmer and continue to simmer the pastry cream for at least a minute.
10. Turn off the heat, add the butter and the bourbon/rum and use a pastry spatula to fold them into the pastry cream.
11. Pour the cream into a glass bowl. Butter a circle in the center of a square of plastic wrap and place the buttered circle directly onto the surface of the hot pastry cream.
12. Refrigerate the pastry cream until cooled completely - at least three hours, but ideally overnight.

Make the cake:

1. Preheat the oven to 175°C.
2. Prepare a cake pan by spraying it generously with oil, and flouring. Be sure all surfaces are coated in flour and then shake out excess. Set aside.
3. Add the eggs and sugar into the Light & Shadow stand mixer, and attach the whisk attachment.
4. Turn to speed 6 and whisk ingredients for 4-5 minutes, or until the mixture is thick and has doubled in size.
5. Reduce speed to stir, and sprinkle ¼ cup of flour at a time into the mixture.
6. Turn off speed after the last of the flour is added, and use a pastry spatula to fold in any remaining flour bits.
7. Pour the batter into the prepared cake pan and bake for 35-40 minutes, or until the cake is deep golden brown and a toothpick comes out clean.
8. Rest in the pan for 10 minutes, run a sharp knife along the sides of the pan to release the cake, then turn out onto a cooling rack to cool completely.
9. When pastry cream is fully chilled and cake is completely cooled, you’re ready to assemble the cake.

Make the ganache: 

1. Place finely chopped chocolate in a medium glass bowl.
2. Heat the cream in a small saucepan over medium heat until it begins to gently simmer, but not boil.
3. Pour hot cream over the chocolate and let it sit for 2-3 minutes.
4. Use a pastry spatula to slowly stir the mixture and all chocolate is melted.
5. Allow to cool for about 10 minutes so that chocolate is thick and smooth, but not watery.
6. Slice the sponge cake in half. With the bottom layer on your cake plate, smooth a thick layer of pastry cream to the edges of the cake.
7. Place the cut side of the top half of the cake directly onto the pastry cream, and gently press the two layers together.
8. Use a pastry spatula to smear pastry cream around the outside edges of the cake (but not on the top), and use your hand to press crushed hazelnuts along the side of the cake.
9. Finally, pour a bit of chocolate ganache into the center of the top of the cake, and gently smooth the chocolate to the edges.
10. Allow to set for a minute or two, and add additional ganache on top to create a thick layer of chocolate.
11. Chill the assembled cake until ready to serve.