Step 1: In advance
Prepare the 14" silver board by brushing the top with a thin coating of piping gel. Roll red fondant 1/8" thick and lift to place on the board. Trim the excess with a craft knife. Glue ribbon around the edge using glue stick. Next, tint 1/4 lb. fondant royal blue and 1/4 lb. fondant yellow. Set aside.
Step 2: Ice tent
For tent roof: Place one 8"cake layer on an 8" round cardboard, adhering with a dab of buttercream. Ice the top of the layer with buttercream and place the 1/2 ball cake on top. Use a cake knife to sculpt the peaked shape by making several downward cuts. ( Note: It will be difficult to get the cake into a perfect point. Pipe a buttercream dollop on top to finish the peak). Ice the tent roof and refrigerate. For tent base: Fill and ice the remaining two 8" layers on the remaining 8" cardboard. Chill both tiers until very firm.
Step 3: Cover and stack tent
For tent roof: Roll a white fondant circle 1/8" thick and large enough to cover the tent roof. Working quickly, drape the fondant over the cake using your hands to smooth and adhere. Trim the excess at the base. Set aside. For tent base: Place the 8" cake on the red base board, adhering with some piping gel. Using blue fondant, roll and cut a rectangle (4" x cake height) and apply to the front of the cake. Roll a white fondant circle, 1/8" thick and large enough to cover the layer with some excess for draping. Taking note where the blue rectangle is, drape the fondant over the cake allowing the fondant to hang away from the bottom of the layer. Use a craft knife to vertically slice the white fondant open in front, revealing blue underneath. Fold back the fondant "doors" and adhere to the cake, using a paintbrush and a little water (secure temporarily with toothpicks if necessary). Trim the edges of the fondant at the bottom of the tent with a craft knife if necessary. Cut 4 straws the height of tent base cake and insert. Pipe some dollops of buttercream on top of the base and stack the tent roof layer on top. .
Step 4: Decorate
Roll yellow fondant 1/8" thick and cut 4 triangles for the tent roof. Adhere with a light coating of water. Use the design tool to stitch the edges. Re-roll yellow and use the scallop cutter to cut trim. Adhere to bottom of tent and stitch with design tool. Roll red fondant 1/8" thick and use the small circle cutter to create polka dots. Use a craft knife to trim to fit if necessary. Adhere with a light coating of water. Re-roll red fondant and use the scallop cutter to create strips of trim. Adhere to the cake, taking care to mask the separation between the stacked layers. Stitch to decorate. Roll blue fondant and repeat process for polka dots using a larger circle cutter. Using food coloring markers, draw a criss-cross pattern on doors and stripes on the tent. Add flags and clown.