Line an 8x8 pan with foil. Place Oreos in the freezer for about 5 minutes and then coarsely chop.
Microwave the frosting on 50% power until slightly runny (about 30-40 seconds). Stir in peppermint extract and gel coloring. You want to make the frosting a little darker than you want the fudge as the chocolate melts will lighten it.
Microwave the candy melts on 50% power stirring every 30 seconds until almost completely melted.
Gently stir the melts and the frosting together. Fold in 1/2 of the chopped Oreo cookies and spread into prepared pan. Immediately top with remaining Oreos and gently press to adhere. Refrigerate 30 minutes and cut into squares or with cookie cutters.
In this size pan, the fudge pieces are about 5/8" thick. If you'd like a thicker fudge, you can double the recipe.