In large bowl, break up cookie dough. Stir or knead in flour until well blended. Reshape into log. If too soft to cut into slices, refrigerate up to 30 minutes. Heat oven to 350°F. Cut dough into 16 (1/2-inch) slices. On ungreased cookie sheet, place slices 2 inches apart. Bake 12 to 14 minutes or until edges are light golden brown. Cool 2 minutes; remove from cookie sheet to cooling rack.
If necessary, remove papers from muffins. Cut 3/4-inch slice from bottom of each muffin to use for bonnet. Reserve muffin tops for snacking. Spread cut side of each muffin bottom with frosting; attach to cookie, frosting side down. Place bonnets on rack over 15x10x1-inch pan.
In resealable food-storage plastic bag, place 1/2 cup frosting. Add green food color; squeeze bag until well mixed and desired color.
In microwavable measuring cup, place remaining frosting. Microwave uncovered on High 30 to 40 seconds or until pourable. DO NOT BOIL. Stir in enough red food color for desired pink color. Pour pink frosting over bonnets in circular motion to cover completely. Reheat frosting as necessary to keep it pourable. Let stand about 10 minutes or until set.
With small spatula, remove bonnets from rack, smoothing edges of frosting. Cut tiny hole in corner of bag with green frosting. Pipe ribbon of frosting for hatband; add bow design. Make dots and flower designs on each hat as desired.