Make sugar cookie dough per sugar cookie mix instructions or using your favorite cutout sugar cookie recipe.
Roll out the dough. Using a butterfly cookie cutter, cut about ¼” thick butterfly cookies. Bake per sugar cookie mix instructions. Allow baked cookies to cool completely.
Make royal icing per instructions. Thin icing to drizzling consistency, or about 6-second icing.
Add 3-tablespoons of thinned royal icing to a small bowl. Add 2 to 3 drops of soft gel paste or food coloring to the bowl, scattering it over the surface of the icing. Drag a toothpick through the drops a few times to make swirls.
Dip the top side of each butterfly cookie directly into the icing, slowly peel the cookie away to one side, turning upright, and let the excess drip off. Transfer to wire rack. Repeat with the remaining cookies, changing icing bowls and colors as desired or when icing gets too muddled.
Allow Marbled Butterfly Sugar Cookies to dry completely before storing or eating. Eat & Enjoy!
Notes
Store Marbled Butterfly Sugar Cookies in an airtight container; will keep 4+ days.¹ Marbled Butterfly Sugar Cookies would also be fab with your fav cutout sugar cookie recipe.