In a large mixing bowl, beat together 1 can of sweetened condensed milk and ½ cup of softened unsalted butter until smooth.

Gradually sift in 4 cups of powdered sugar while mixing on low speed until all sugar is incorporated.

Stir in 1 teaspoon of peppermint extract and add food coloring if desired, mixing until even.

Refrigerate the dough for 10-15 minutes if too soft to shape.

Roll portions of the dough into 1-inch balls or use cookie cutters for shapes.

Let the mints set at room temperature for 1 hour to firm up.

Transfer mints to an airtight container for storage.