An awesome birthday cake

I came across a similar cake in a party-food book and was immediately taken by it ignoring the more than obvious fact that it was meant for a kids birthday party. Kids have fairly simple taste buds: as long as it's sweet and with extra sugar icing on top, they'll love it. So the dense quatre quarts dough should do the trick for them. Adults are a bit more fussy, or at least my friends are. Some of them criticised the density of heaviness of the cake. But let's face it: I didn't bake the cake for it's culinary quality but simply for the look. And damn, it did look good.
An awesome birthday cake:
: 1 kg self raising flour
: 1 kg castor sugar
: 1 kg butter
: 15 eggs

Filling:
: 250ml strawberry jam
: 250g butter
: 500g icing sugar

Topping:
: 500g icing sugar
: Smarties, strawberry laces, Jellie Babies, sugar hearts, Maltesters, Jelly Beans etc.

Make the dough in two batches (easier than making it all at once) and divided it between a 25cm, 20cm and 15cm cake tin and a muffin cup. Bake until ready and let cool on a wire rack.
Heat the jam with a little raspberry vodka, then spread it evenly over every cake. Now make the butter cream by mixing the softened butter and 3 tbsp of hot water with the icing sugar. Spread on top of the jam. Finally stack the cakes on top of each other (obviously starting with the largest cake at the bottom).
For the icing, mix the icing sugar with just enough water to make the mixture slightly runny, then cover the entire cake with the icing before adding the decoration.