Stir yellow food color into 3/4 cup frosting to make yellow. Remove baking cups from 2 cupcakes. Place 1 cupcake, rounded side down, on cake for fairy cottage. Spread 2 teaspoons yellow frosting on cupcake; top with another cupcake, rounded side up. Spread yellow frosting on top and sides of cupcake stack. Place 3 cookies on rounded top of cupcake, using remaining yellow frosting to stick them together. Place remaining cookies on cake as shown.