Swiss Roll Sponge:
- 12 large eggs (separated, room temperature)
- 300g Selati castor sugar
- 70g cornfl our
- 200g Supreme cake fl our
- 2 teaspoons baking powder
- 2 teaspoons vanilla extract
- Selati icing sugar (for dusting)
- Salted Caramel Buttercream:
- 225g egg whites (room temperature, ± 6 eggs)
- 340g Selati castor sugar
- 750g unsalted butter (cut into blocks, softened)
- 400g tinned caramel or dulce de leche spread
- 1 teaspoon sea salt flakes
- Pre-heat the oven to 180°C / 160°C fan. Grease and line 2 large 20 x 30cm baking trays with baking paper. In a large, clean bowl, whisk the egg yolks and 240g castor sugar until the mixture is very thick and pale (± 10 minutes).
- Fold in the vanilla and sifted cake flour, cornflour and baking powder. In another bowl, whisk the egg whites until soft peak stage, then slowly whisk in 60 ml / ¼ cup of castor sugar. Lightly whisk 1⁄3 of the whipped egg whites into the egg yolk mixture to lighten it, then fold in the remaining egg whites, taking care to knock as little air out as possible.
- Divide the batter evenly between the 2 baking trays and bake in the preheated oven for 15-20 minutes or until just turning golden and springy to the touch – be careful not to overbake or the sponge will crack when rolled.
- Remove the cake from the oven and allow it to cool a little before turning it out, bottom-side up, onto another piece of baking parchment which has been dusted with icing sugar.
- Place the egg whites and sugar in a bowl that fits over 1 of your saucepans.
- Fill the bottom of the saucepan with water and bring it to a gentle simmer.
- Place the bowl with the egg and sugar over the hot water and stir gently with a whisk (don’t whisk to aerate the mixture).
- Keep stirring until the mixture reaches 60°C on a thermometer or until the egg is hot to the touch.
- Transfer the hot mixture to the bowl of a stand mixer and using the whisk attachment, whip the mixture on high until light and fluffy.
- Continue whipping for a good 10 minutes or until the meringue is cool to the touch.
- Slowly add the butter 1 block at a time. Stir in the caramel.
- Cut the cake in half horizontally so you have 2 long strips.
- Lay the 4 cake strips end-to-end, with the short side closest to you, to form 1 long strip.
- Spread the caramel and buttercream over evenly, leaving a border at the end furthest from you.
- Repeat the process with the rest of the buttercream and caramel, leaving enough buttercream to cover the outside of the cake later. Roll the cake up tightly from one end. Trim off the ends if necessary. Place the cake cut-side down on a cake stand and refrigerate for 1 hour to set.
- Remove the cake from the fridge and frost the entire cake with the rest of the buttercream.
- Serve with a ball of spun sugar on top for a touch of whimsy.