My oldest son is an aspiring member of the 501st Kilted Trooper Brigade. This cake was for his bagpipe camp. The kids really loved this because it had cake and brownies together.
1. Make batter from 2 box cake mixes, same brand/flavor. Bake in the largest Wilton Paisley cake pan. See: http://www.wilton.com/store/site/product.cfm?sku=2105-4039 Tip: this cake pan set is dead useful - I've done tons of cakes with this shape, including the scuba cake, Holidays on Hoth, Death Star base, artist palette, etc. Love these pans!
2. Bake a double batch of brownies is a 9x13 or larger rectangular pan. I use Betty Crocker Original Supreme Brownies - add an extra egg for "cake like" brownies.
3. Place cooled cake on a large cake board. Do not level. (The rounded nature of the cake looks great.)
4. Make standard Buttercream icing, tint color of your choice. I went for a burgundy, but green or blue would be good too. Cover the entire cake with open stars, using a Wilton No. 16, 18 or similar tip.
5. Cut the cooled brownies into stripes. Tip: for perfect cut brownies, use a plastic knife. (The kind that comes in a box of plastic cutlery at the grocery store or a fast-food place.) Arrange the brownies for the drones, blowpipe and chanter as shown. Shape ends of blowpipe and chanter as shown. For the chanter, use a Wilton tip to cut 7 depressions, for the holes. Put the tip about 1/4" in and twist to extract a bit of the top of the brownie.
6. Using a Wilton No. 3 round tip or similar, pipe the chords around the tops of the drones as shown. You can either pipe the tassels or use a bit f fondant tinted to match. (I tinted a bit of fondant and squeezed it through my garlic press to get a group of stands that made the tassels here.)