Have a good picture handy to help with decorating.
1. Bake 8 round layers (8” is best, 9” okay).
2. Level each layer. See: http://www.wilton.com/cakes/making-cakes/leveling-cakes.cfm Do not skip this step! Otherwise your cake will not be straight or stable!
3. Using cake circles, create 4 2-layer cakes with buttercream icing between each layer. Crumb coat with icing.
4. Stack 3 of the cakes (to make a 6 layer cake) using dowels to separate each cake. See: http://www.make-fabulous-cakes.com/tiered-cakes.html Do not skip the dowels! Your cake cannot stand without dowels!
5. To make cake pictured, cover with while rolled fondant. See: http://www.wilton.com/decorating/fondant/rolled-fondant.cfm This is pretty tricky to do on such a tall cake, so it may take some practice. Be sure the icing is dry before you lay the fondant on it. Use a high quality fondant, such as Satin Ice - see my Rolled Fondant post for details. Alternative 1: cover the 2 layer cakes with fondant, and just cover the "seam" with decorations. Alternative 2: frost smooth with white icing.
6. Put the last cake on a thick silver cake drum. Using a serrated knife, cut the dome shape. Alternative, you can bake the last layer in a Pyrex bowl. Frost with gray buttercream, and/or cover with gray rolled fondant.
7. Tint fondant blue and gray. Cut shapes from fondant for details (use sharp paring knife, cookie cutters). Attach to cake by brushing very lightly with water. (small brush or damp finger)
8. The red “eye” is the ball from my “track ball” style mouse. It really looked good – see if you have something handy to use for this! Or else use a fondant sphere, rub with vegetable oil to make the ball shiny.
9. Decorate base with balls of fondant.
10. Create arms out of Styrofoam or Rice Crispy treats, cover with fondant, decorate and position.
Note – this cake is pictured on a stand using for decorating from Joann’s or Michael’s – it made a perfect base for R2!