Preparing the Sponge Cake
- To make the sponge, preheat the oven to 190 degrees Celsius (170 if you’re using a fan-forced oven). Grease and line 4 x 20cm cake tins with baking paper. If like me, you don’t have 4 (who does), you’ll have to reline and bake the cakes in batches (which is perfectly okay).
- Using an electric handheld or stand mixer (with the paddle attachment), place the butter, sugar, flour and baking powder in the bowl and mix on low speed until it resembles a sandy breadcrumb texture.
- Whisk together the milk, vanilla and eggs then, with the speed still on low, gradually pour the liquid into the dry ingredients. Beat the batter until smooth and light – about 2 minutes.
- Divide the cake batter in between your lined tins (if you’re OCD like me you can weight it so they’re all even – I used 400g in each of my tins).
- Bake in the preheated oven for 20-25 minutes or until golden, springy to the touch and a wooden skewer comes out clean. Allow the layers to cool completely before levelling them off by cutting off the tops with a bread knife. Allow to completely cool before use.
Preparing the Cocoa Crumble and Espresso Syrup
- For the cocoa crumble; combine all the ingredients in a medium bowl and spread out evenly on a lined baking tray. Bake in a 180 degrees Celsius (160 if you’re using a fan-forced) oven for 15-20 minutes. Allow to cool.
- To make the espresso syrup; brew the espresso and stir in the sugar until completely dissolved.
Preparing the Mascarpone Frosting
- For the mascarpone frosting; Using an electric handheld or stand mixer (with the paddle attachment) cream the butter and icing sugar together until light and fluffy – about 9 minutes.
- Then add the cream cheese and vanilla extract and beat until smooth.
- Fold in the mascarpone, don’t overmix.
- Place the frosting into a piping bag with a plain nozzle.
- To assemble the Tiramisu Crunch Cake: make a collar that’s 22cm long and 15cm wide out of acetate or double folded baking paper and insert it into the same springform cake tin you used to bake the cakes.
- Place the first layer of cake in the bottom of the cake tin.
- Brush generously with espresso syrup (don’t be afraid to really soak it as this is what will make it taste like tiramisu!), pipe a layer of frosting to cover the base and sprinkle with the cocoa crumble.
- Repeat this process until all the cake layers have been used. Make sure that each layer is pressed down properly.
- Finish the cake with a layer of frosting and the cocoa crumble.
- Place in the freezer for a minimum of 6 hours or until the frosting is firm.
- To unmold, remove the Tiramisu Crunch Cake from the cake tin, peel of the acetate and allow it to come back to room temperature before serving with a dark chocolate sauce.