To prepare a copycat thin mint cookies recipe, first you need to gather your ingredients. First, you'll need the following ingredients: 14 cup granulated sugar 2 tablespoons unsalted butter 1 tablespoon vanilla extract 1 teaspoon kosher salt 2 teaspoons baking powder 1/2 cup confectioners' sugar (optional) Preheat the oven to 375?F (190?C) and prepare your cookie sheet. Line the bottom of the baking sheet with parchment paper and set aside. Using an electric mixer, cream together the butter and sugar until light and fluffy. Add the egg and vanilla and beat until combined. Gradually add the dry ingredients to the wet mixture and mix until the mixture is just combined and no dry streaks remain. Bake the cookies for 12 to 15 minutes or until they're golden brown. Remove from oven and allow to cool before serving.