Hi I am making a layered 3D cake for my daughter think I have worked out the sculpting side of things from previous forums??! 

The cake will only be 15cm in diameter & about 20 cm high.  It will be sitting on a square dummy cake 'present'.Will I need to do the same stacking technique as for a tiered cake or do you think the top is small enough to hold together with a dense recipe? 

Also, I have never covered a cake in royal icing - always fondant. Can anyone tell me whether I need to crumb coat the finished shape before i cover it in RI. The effect will be "furry"!

Organised as I am I have to start baking later today so advice would be greatly appeciated thanks in advance