Tiramisu Cake

For Vanilla Sponge Cake

• 163 g (1 1/4 cup) Plain flour/all-purpose flour
• 1/4 tsp Salt
• 6 g (1 1/2 tsp) Baking powder
• 16 g (2 tbsp) corn flour/corn starch
• 2 eggs UK-medium size/US large (total weight = 108g without shell)
• 1 1/2 tsp vanilla extract
• 150 g (3/4 cup) granulated sugar
• 100 g (1/2 cup) vegetable oil
• 120 ml (1/2 cup) buttermilk

For Coffee Soak

• 1/4 cup (60 ml) boiling hot water
• 2 tbsp granulated sugar
• 1 tbsp instant coffee

Mascarpone Whipped Cream Frosting

• 240 g (1 cup) Whipping cream, chilled
• 240 g (1 cup) Mascarpone cheese, straight from the fridge
• 1 tsp vanilla extract
• 2 tbsp honey
• 60 g (1/2 cup) Icing sugar/ powdered sugar

For Decoration

• 1-2 tbsp cocoa powder

For Vanilla Sponge Cake

1. Grease a 7-inch round cake pan with butter or oil, and line the bottom and sides with baking paper as we need smooth sides of the cake.
2. Preheat the Fan oven to 155C/311F (For a conventional oven, 175C/347F).
3. In a large bowl, sift together the plain flour, corn flour, baking powder, and salt. Set aside.
4. To make buttermilk, take 120 ml (1/2 cup) milk (at room temperature) and add 1 1/2 tsp lemon juice, stir to mix and set aside for a few minutes before adding to the batter.
5. Meanwhile beat the sugar and eggs together on medium speed until they become light, thick, and fluffy, reaching the ribbon stage. This should take about 5-8 minutes. Make sure to scrape the bowl so everything gets well mixed in.
6. Add in the vanilla extract, vegetable oil and buttermilk. Beat again to combine.
7. Add in the dry ingredients, and beat again on low until just combined. Be careful not to overmix the batter if you want light and airy crumbs.
8. Pour the batter into the prepared baking pan and tap the pan on the counter to remove the air bubbles.
9. Bake in the preheated oven for 40 minutes or until a tester inserted in the centre of the cake comes out clean.
10. Remove from the oven and let it cool in the pan for about 10-15 minutes before removing it from the pan onto a wire rack to cool completely.

For Coffee Soak

1. Combine the instant coffee, sugar, and boiling hot water. Stir until the coffee and sugar have fully dissolved. Set aside.

For Mascarpone Whipped Cream Frosting

1. Chill the mixing bowl. Pour chilled whipping cream into the bowl, and whip on medium until firm peaks form (about 3-4 minutes).
2. Take out the cold Mascarpone cheese straight from the fridge. Give it a good mix in a bowl with vanilla extract and honey before adding to the whipped cream. Then add it to the whipped cream, and whip until stiff peaks form (a stiff peak means if you turn your bowl upside down, it won't fall out). It will happen quickly, so keep an eye on it. Once done, It is ready to use. Use it right away.

Assembly

1. With the help of a long serrated bread knife, horizontally cut the cake into 2 layers. Place the first layer of cake on the cake stand or your serving plate (I used a cake turntable with baking paper and after frosting, transferred the assembled cake to a cake stand). Prick the top with a fork or toothpick, then generously soak it with coffee syrup using a pastry brush or spoon.
2. Spoon the frosting onto the cake top, then spread it out evenly using an offset spatula. Place the next cake layer on top and repeat the process. Cover the top and sides of the cake slightly with the frosting.
3. With the remaining frosting, fill a piping bag fitted with a 1A nozzle. Pipe the blobs across the top of the cake.
4. Refrigerate the frosted cake for 3-4 hours minimum (or overnight preferably).
5. Dust with cocoa powder using a sifter just before serving.
6. Make slices with a sharp knife and enjoy!