Step 1 Two days in advance: Make cookies. Roll out dough 1/8" thick.

Step 2 Using patterns, cut ten buildings in each size.

Step 3 Using cutters, cut train engine, two cars, airplane (trim off wings and bottom of tail; bake wings separately) and three trucks (cut front end off two trucks to make passenger cars for train). Bake and cool cookies.

Step 4 Prepare two recipes of Color Flow icing according to Wilton® Color Flow Mix package directions. Outline and fill in cookies with Color Flow. Let dry overnight.

Step 5 When dry, pipe details with full-strength Color Flow.

Step 6 Add tip 3 dot lights on vehicles and tip 1 outline spokes on train wheels. Overpipe roof of train cars with tip 3.

Step 7 Pipe tip 3 outline windows on buildings (pat smooth with finger dipped in cornstarch).

Step 8 Ice smooth 2-layer 14" cake (bake two 1½" layers to make a 3" high cake) and 3-layer 8" cake (bake one 2" and two 1½" layers to make a 5" high cake). Prepare cakes for stacked construction.

Step 9 Make fondant train track. Tint 12 oz. fondant black; reserve remaining white. Roll out black fondant 1/8" thick; cut ¼" strips for outer rail. Pipe a thin line of piping gel along edge of foil-wrapped foam board; attach outer rail strips. Cut and attach inner rail the same way, positioning 1" from outer rail. For cross rails, cut ¼"x1" black strips; attach with piping gel.

Step 10 Using patterns, cut cloud and train smoke from cardstock; print messages with marker.

Step 11 Cut lollipop sticks to 3" long; attach to back of train smoke cloud with full-strength Color Flow; let dry.

Step 12 Attach wings to plane cookie with full-strength Color Flow; let dry.

Step 13 Attach lollipop sticks to three building cookies for cake top with full-strength Color Flow, leaving 5" extending to insert in cake; let dry. Attach stick and cloud to plane with full-strength Color Flow; let dry.

Step 14 Cut two lollipop sticks to 4" and attach to cars and truck, leaving 3" extended; let dry.

Step 15 Cut ¼"x½" strips of black fondant for lane dividers; position on 14" cake top, attach with damp brush 2" apart.

Step 16 Roll balls of white fondant; with Color Flow, attach to backs of train cars for additional support.

Step 17 Attach buildings and train cars to cake sides with dots of icing. Insert cars and truck in 14" cake. Insert buildings and plane on sticks in cake top.