Caramel Cake
·Tip: batter quantities for a baking sheet
I always use the same sponge recipe and just adjust the ratio of eggs (and other ingredients) to the size of the tin. For one baking sheet: use batter made with 4 eggs for a base sponge layer (the kind used under gelatine-set fillings). For one baking sheet: use batter made with 6 eggs for a sponge that will be sliced and filled.
Tip: batter quantities for a cake tin
26 cm round cake tin – batter made with 6 eggs. 30 cm round cake tin – batter made with 8 eggs.
Tip: flavouring the sponge
The sponge can be flavoured with nuts, coconut, almonds, cocoa or chocolate. Whatever ingredient you mix into the flour needs to weigh the same as the eggs you're using. I used 50 g of finely ground hazelnuts in place of 50 g of the fine plain flour.
Weighing the ingredients (6 eggs, 55 g each)
Weigh your eggs in their shells (however many you plan to use), then measure out the same weight in caster sugar and the same weight in fine plain flour. Allow 2 tablespoons of hot water per egg.
Egg yolk foam and whisked whites
Whisk the egg yolks with the sugar and water. Once the mixture has thickened and the sugar has dissolved, whisk the egg whites to stiff peaks and fold them into the yolk mixture alternately with the flour.
Hazelnuts
Fold in the ground hazelnuts, or your chosen flavouring.
Bake
Pour the batter into a greased and flour-dusted baking tin. Bake in an oven preheated to 175 °C (160 °C fan). Baking time depends on the size and thickness of the sponge, but it's usually somewhere between 30 and 50 minutes.
Skewer test
Don't open the oven for the first half hour, or the sponge may sink. After that, you can open the door and test the centre with a skewer – it should come out clean.
Cooling and slicing
Let the sponge cool completely. Only once it's fully cool should you slice it horizontally into as many layers as you like, depending on how tall it is.
Caramelising the sugar
Bring the cream to the boil in a saucepan. Put the sugar in a second saucepan, turn the heat up to almost full, and wait for the sugar to melt. I'd recommend using a stainless steel pan – a non-stick one can easily get ruined by this. The sugar will gradually turn into a lovely caramel.
Watch the heat and the colour
Keep an eye on two things: don't burn yourself (hot caramel really hurts!), and don't let the caramel get too dark – if it scorches, it will turn bitter.
Stir in the butter and salt
Take the finished caramel off the heat and stir in the butter – I use plain butter – along with about a teaspoon of salt, or more or less depending on how salty you like your caramel. Stir until everything is fully combined.
Add the cream and stir
Return the pan to the heat and stir over a gentle temperature. Slowly pour in the hot cream, stirring continuously until you get a smooth caramel mixture. Leave it to cool completely.
Whip into a cream
Whip the softened butter together with the cooled caramel. Beat for a good while, around 8 minutes. Add the mascarpone and whip again thoroughly until you have a smooth, silky cream.
Filling and decorating
Spread a generous layer of cream between each sponge layer. Stack the cake together, then cover the top and sides with cream as well. You can sprinkle it with sponge crumbs and decorate however your imagination takes you.
