1. Preheat oven to 350 degrees F. Line two cookie sheets with parchment paper. Knead sugar-cookie dough and flour until smooth. Roll dough until it's 1/4-inch thick. Using a 3-1/4-inch heart cookie cutter, make 16 shapes, rerolling dough if necessary. Transfer the hearts to cookie sheets. Insert a long lollipop stick about 1 inch into dough.
2. Tint the remaining dough yellow with the food coloring. Roll until it's about 1/4-inch think. Cut 16 rectangles 1 inch by 2 inches. use a small pairing knife to make a zigzag design along the top to form the crown. Transfer the crowns to the cookie sheets. Sprinkle hearts with white decorating sugar and the crowns with yellow sugar. Bake until cookies are just golden, 10 to 12 minutes. Cool completely on a wire rack.
3. Pipe on chocolate frosting to make ears, eyes, and whiskers, and to attach the jelly-bean nose and cookie crown. Refrigerate ten minutes, or until chocolate is set.