This is one of those traditional bakes that everyone's going to love. Soft and fluffy vanilla cake layers filled with light and airy diplomat cream and fresh strawberries. Delicious!
Preheat your fan oven to 160°C (325°F) or 175°C if you’re not using a fan oven. Grease and line with parchment paper two 8" (20 cm) round cake tins.
In a medium bowl sift together flour, baking powder and salt. Whisk until combined and set aside. In a measuring jug combine sour cream and vanilla extract. These are your wet ingredients.
In a bowl of a stand mixer fitted with a paddle attachment, cream the butter and sugar on a medium-high speed until pale and fluffy. (approx. 3 min) Stop the mixer and scrape down the bowl.
Turn the mixer to medium-low speed and add eggs one at a time – making sure it’s fully incorporated after each addition. Stop the mixer and scrape down the bowl.
Add your dry ingredients, mix until everything is just combined. In the end add sour cream and vanilla extract.
Divide the batter evenly among the 2 tins and bake for 20-25 minutes or until skewer inserted in the middle comes out with few moist crumbs. Do not overbake it.
Once they’re done, let the cakes cool for 10-15 minutes on a wire rack before removing them from the pans to cool completely. They will continue to cook in the pan, so it’s important that the skewer is not entirely clean. Otherwise, you’re cake will overbake and that will cause dryness.
for diplomat cream
In a medium sized bowl, using a whisk, mix together egg yolks, egg, sugar, cornstarch and salt. Add a couple of tablespoons of previously measured milk to thin the mixture out.
In a heavy bottomed saucepan bring the milk to a simmer. Pour over the egg mixture in a slow and steady stream, whisking constantly so you don't scramble the eggs. This is called tempering.
Pour the eggy milk mixture back into the saucepan and heat it until it thickens, whisking constantly. This will take approx. 5-6 minutes. When it's done, strain it through a sieve to a bowl. Add vanilla extract and mix until everything is incorporated. Cover with cling film touching the surface to prevent "skin" forming. Leave the pastry cream to cool in the fridge. It will thicken quite a bit, that's okay.
Using a hand mixer, mix very cold heavy cream to a soft peak. Add it to cold pastry cream and mix everything until combined. Scrape and fold with a silicone spatula at the end so there are no white streaks of heavy cream.
assembly
In the middle of your cake board or a serving plate put some diplomat cream to stop the cake from moving around. Choose your prettiest cake layer as the top one.
Place one cake layer on a cake board or a serving plate. Using a small offset palette knife spread the diplomat cream over the cake. Using a piping bag fitted with Wilton 2A round tip make little blobs around the edge. Place sliced strawberries on top of the filling and put a second cake layer on top.
Decorate it either with leftover diplomat cream or whipped heavy cream and the rest of fresh strawberries.