To mark staircase: Mark center of 6 in. cake with toothpick. Make another mark 1 in. to the right and score a vertical line to bottom of base cake for right edge of staircase. Mark left edge of staircase with toothpick using these dimensions-top stair is 7 1/2 in. wide, stairs 2 through 6 are 8 in. wide, stair 7 is 9 in. wide, bottom stair is 9 1/2 in. wide. For top of 6 in. cake, cut a 3 1/2 in. circle of gray fondant; attach with damp brush. Each cake will have an upper and lower stair. For each upper stair, cut two 1 x 1/4 in. deep strips x width of each stair. For each lower stair, cut a rectangle 1 in. high x 3/4 in. deep x the width of each stair. For each lower stair you will also need 1 top tread strip (cut 1 in. high x 1/8 in. thick x the width of the rectangle piece) and 1 side wrap strip (cut 1 in. high x 1/8 in. thick and 1 1/2 in. wider than rectangle piece).