Scottish Shortbread Cookies
["1/4 c. confectioners sugar", "1/4 c. granulated sugar", "1 1/4 c. butter (2 1/2 sticks), refrigerated and cut into 8 or 10 pieces", "2 1/2 c. all-purpose flour"]
["Preheat oven to 275\u00b0.", "Place sugar in food processor and process until very fine.", "Add butter.", "Pulse until sugar disappears.", "Add flour, pulse until flour disappears.", "Mixture will be moist and crumbly.", "Place into a plastic bag.", "Press together to form dough."]
["confectioners sugar", "granulated sugar", "butter", "flour"]