Nope easy as

ok so it works best as a layer cake (just 2 cakes joined with buttercream in the middle)

so just lightly grease 2 x 20cm cake tins (one at a time if you only have 1)

bake for 35mins until a skewer comes out clean.

If you don't want to do it as a layer cake just bake 2 cakes :-) - you can freeze the uniced cake...