• Preheat the oven to 180℃. Prepare 2 greased cake tins with a diameter of 21 cm.
• In a bowl whisk together butter and sugars until light and fluffy. Whip for 4-5 minutes. Add oil and whip again.
• Add eggs – one at a time while whisking. The batter should be creamy. Whisk until fully combined.
• Mix flour, cornstarch and baking powder into another bowl. Add ⅓ of the flour mix into the batter, mix well. Pour ½ of the milk and mix again. Continue until the flour mix is added as last.
• Pour the batter into cake tins and bake for 30-45 minutes or until the toothpick comes out clean. Let the cakes cool completely. Take them out of the cake tins after 20 minutes. Cut these 2 cake layers into 4 cake layers. For the easier decorating - I usually put the cakes in the freezer or at least to the fridge for an hour.

Cream

• Cream the butter with mascarpone in a bowl until it's creamy but not separated. When you cream these two, they usually get apart after a long time of mixing, and leak water. Cream them for 2 minutes, scrape the bowl and mix for another 2 minutes. Add sugar and mix on low speed for 5 minutes.
• Add raspberry syrup and mix until everything is combined. I added red food colouring at the end and mixed the cream for a few extra minutes.
• Now place the cake layer on the plate. Add a thin layer of butter on top of the layer. Then add a thick layer of buttercream on the edge and put raspberries in the middle. Repeat the process until you're left with the last cake layer on top and sides. Put the cake into the fridge for at least 6 hours or overnight.