• Sponge:Preheat the oven to 170 Degrees C
• Separate the eggs into egg whites and egg yolk
• In a bowl mix the softened butter with the first portion of sugar
• Once the butter and sugar mix becomes light in colour and creamy, add in the egg yolks and mix until well combined. 
• Pour in the milk and mix until it's well dissolved
• Sift in the plain flour and corn flour
• Mix until there are no more lumps (avoid over mixing or the sponge will become dense and heavy)
• In a separate bowl, beat the egg whites whilst gradually adding the second portion of sugar until it reaches stiff peaks.
• Carefully fold the yolk mixture into the egg white mixture until it's well combined without deflating the batter
• Line the pan with a circle cut out of baking paper at the bottom and use butter the grease the sides
• Pour the batter into the tin and bake for 40 minutes at 170 degrees C.
• Once complete, take the cake out of the oven
• Use a small knife or spatula to go around the cake and remove it from the tin.
• Leave the cake rest upside down on a cooling rack for 20-30 minutes until it's fully cooled down (otherwise you risk to melt your icing)
• Using a bread knife or cake leveller, cut the sponge into 2 layers
• Optional: I also cut out the outer golden 'skin' layers of the sponge, keeping only the pale sponge insides so that it looks prettier

Icing & Assembly

• While waiting for the cake to cool down, you can start making the icing and cut the strawberries
• In a bowl, add the whipping cream (or double cream) mascarpone and sugar then using a hand mixer mix until you get a thick icing texture, be careful not to over-whip for too long otherwise the icing will break apart and won't be as smooth - you can add some more cream or mascarpone to fix this
• Slice some strawberries
• Using a turntable (optional, but it will make the icing phase much easier), place the first layer of sponge then add a layer of cream, followed by a layer of sliced strawberries then topped with another layer of cream. 
• Use a spatula to even out the cream layer, then add the second layer of sponge on top
• Cover the rest of the cake with the remaining whipped cream and decorate with strawberries