Prepare 2 chocolate cake mixes as directed on box.
Pour enough batter into greased and floured 16" round cake pan to just slightly above half (do not over-fill pan). Any remaining batter can be used for cupcakes.
Bake as directed on box for an 8 1/2" x 13" pan. Then add 5-minute intervals until toothpick comes out clean. Cool completely.
Prepare 2 confetti cake mixes as directed. Pour into a doll-dress mold and bake as per mold's directions. Cool completely. Again, remaining batter can be used for cupcakes.
Prepare frosting in separate batches so it doesn't harden while decorating. Beat shortening & vanilla on medium speed for 30 seconds. Slowly add half of the powedered sugar, beating well. Add 2 tbsp milk. Gradually beat in remaining powdered sugar and enough remaining milk to make right consistency. Add food color of choice.
While "dress" cake is still in pan, trim off raised portion of cake and and brush off loose crumbs. Remove both cakes from pans. Put 16" round cake on large serving board. Place "dress" cake in the center of the round cake using frosting to secure.
Using a decorating Bag and starburst tip, pipe frosting on entire cake, using preferred colors and design, starting at the bottom and working to the top. Make additional batches of frosting if needed.
To make hat fringe, put colored gum balls around the bottom of the cake using dollops of frosting to secure them directly to the serving board. Let the fiesta begin!!