Mix the eggs, butter, oil and sugars in a bowl until pale and fluffy - it takes 3-5 minutes.
Sift in the flour, spices, baking powder, baking soda and salt and mix just until smooth.
Fold in the rest of the ingredients.
Scale the batter equally between two 18cm diameter cake pans lined with baking paper.
Bake in the preheated oven at 170C for 45-50 minutes.
Allow the cakes to cool down then even the top out. Cut each cake in half to obtain 4 discs of sponge cake. Place aside.
Cream cheese buttercream:
Mix the butter until pale and light. Add the powdered sugar and keep mixing until fluffy.
Stir in the orange zest and vanilla extract. Give it a good mix.
Soften the cream cheese slightly by mixing it. Split the buttercream in half.
Mix one half of buttercream with cream cheese. Preserve the remaining buttercream to cover the cake later on.
Place the cream cheese buttercream in a pastry bag fitted with a round nozzle.
Start layering the cake on a cake board: a disc of sponge, followed by a layer or cream cheese buttercream and so on.
Once finished, place the cake in the fridge for 30 minutes then start covering it in a very thin layer of buttercream - this is called crumb coating and its purpose is to keep in place all the crumbs of the cake.
Place in the fridge for 30 more minutes then cover with a second layer or buttercream. Keep working the buttercream until it is smooth and the angles are straight.