Recipe from The Frog Commissary Cookbook   Coffee Walnut Chocolate Chip Muffins Ingredients 1/2 cup butter 1/2 cup brown sugar 1/2 cup white sugar 3 tablespoons instant coffee 2 teaspoons vanilla extract 2 eggs 2/3 cup milk 1 3/4 cup flour 1/2 teaspoon salt 1 tablespoon baking powder 3/4 cup chocolate chips 1 1/2 cups