Igloo Cake

1 box of yellow cake mix
1 pound white chocolate chopped
1 8 oz white sanding sugar
2 tubs vanilla frosting
2 drops blue food coloring
1 cake doughnut

Butter and flour 8 inch round pan, and a 1.5 quart oven proof bowl. Make cake batter, divide between pan and bowl. Bake at 350* for 35 minutes pan and 40 minutes bowl.
Microwave the white chocolate until melted. Pour onto a parchment line baking sheet and spread 1/4 inch thick. Sprinkle with sanding sugar. Chill for 10 minutes. Remove chocolate from fridge. Break most of it into rough 1/2 -1 inch pieces. for the ice that cover the igloo. Cut some into even 1/2 inch square for the tunnel entrance.
Assemble the igloo:Mix 2 1/2 cups of frosting with blue food coloring. Spread some blue frosting on the flat cake, the cover with the bowl shaped bake. Spread some frosting on the cake where you want the tunnel to go. Then attach half the doughnut, add more frosting to the doughnut, and add the other half of the doughnut. Cover the entire cake with a thin layer of blue frosting. Chill for 15 minutes. Spread the remaining blue frosting over the cake. Arrange the white chocolate pieces on the igloo. Place the even squares on the tunnel.