I was going to say that baking a snowman cake should be easy, make white fluffy icing and stick in sweets like you would stick coal/carrots/etc into a real snowman.
Than I looked at the cake tin. It looks very intricate, would a cake even come out of the pan with all that shape? And then if you put icing on top all the 3d-ness would be lost. Personally I would look for a 3 circles type snowman shape if I was desperate for a snowman cake.
I'm hoping that someone else will come along and expklain how it's actually very easy, but that looks like a jelly mold to me.
PS Is it mold or mould for jelly?