Bake and cool mini cakes; taper to 1 in. diameter at top and 3 1/4 in. at bottom.
Roll out fondant 1/16 in. thick as needed. Prepare and cover cake with fondant. Insert doll pick. For bodice front, cut a 3 x 1 1/2 in. wide strip and attach, trimming off excess. For collar, cut a 1 1/2 x 1/4 in. wide strip. Attach at neckline, trimming ends where they meet in the back. For sash, cut a 4 x 3/8 in. wide strip. Center and wrap around waist; fold over at center back, letting ends hang down.
Use pattern to cut sleeves. Fold over outstretched arms. Secure to top edge of dress using damp brush; pinch strip together under arms. Paint skin areas with Color Dust. Use FoodWriter markers to draw scary facial features.