Assemble this edible jigsaw puzzle with two baking tricks. One, add flour to ready-made dough for durability, and two, partially bake the dough before using the cookie cutters, to help the pieces keep their shape. Choose any shapes and colors you like to celebrate a birthday, commemorate a holiday, or just sweeten up a long afternoon.
To make the puzzle: Heat the oven to 350 degrees and line a rimless baking sheet with parchment paper. On a floured surface, knead 1/3 cup flour into a 16-1/2-ounce tube of sugar cookie dough (we used Pillsbury). Reserve half for later use. Roll the dough on a floured surface to a 1/4-inch thickness, then cut it into three 4-inch squares. Place the squares on the baking sheet and chill them in the refrigerator for 15 minutes. Bake the cookies for 10 minutes. Remove the sheet and immediately slide the parchment paper onto a counter or cutting board. Push the cookie cutters into the dough (warning: It will be hot!); be sure to cut all the way through. Slide the paper back onto the sheet and bake 2 more minutes. Let the cookies cool.
To frost: Thin a cup of white frosting with a small amount of water until it's the consistency of honey. Divide it into small bowls and stir in food coloring (we used Betty Crocker Classic Gel Food Colors) with a toothpick. Frost the cookies with a paintbrush.