A batch of vanilla cookie dough is tinted two different colors to create these Christmas trees.
Preheat oven to 350 degrees. Tint dough with food color as desired. Shape dough into 2 disks, and wrap each in plastic wrap. Refrigerate until firm, about 1 hour.
Roll out 1 disk on a lightly floured piece of parchment to a 1/8- to 1/4-inch thickness. Repeat with remaining disk. Refrigerate until firm, about 30 minutes. Using a tree cutter, cut out trees. Using a #12 Ateco pastry tip, cut out ornaments within trees. Working with dough in a contrasting color, use the same rectangular cutter to cut out puzzle pieces that fit within cutouts. Transfer all shapes and pieces to parchment-lined baking sheets. Refrigerate until firm, about 30 minutes. Fit puzzle pieces into cookies. Refrigerate 30 minutes more.
Bake until cookies are firm, 12 to 15 minutes. Transfer sheets to wire racks; let cool completely.
Try one of our cutout cookie variations: Stained-Glass Snowmen, Stained-Glass Wreaths, Sugared Wreaths, Fluted Wreaths, and Cookie Houses.