Beat butter and sugar at medium speed with an electric mixer about 5 minutes or until creamy. Add egg yolks and vanilla, beating until blended. Combine flour, cocoa, and salt; gradually add to butter mixture, beating until blended after each addition. Cover and freeze 30 minutes.
Roll dough to a 3/8-inch thickness on a lightly floured surface. Cut desired shapes using favorite seasonal cutters; place on lightly greased baking sheets, allowing space for craft sticks. Insert 1 craft stick into bottom of each cookie.
Bake at 350° for 10 to 16 minutes or until edges are golden. (Baking times may vary with different cookie shapes and sizes.) Cool 5 minutes on baking sheets. Slip a metal spatula under cookies to loosen; cool completely on baking sheets.
Spread a generous amount of Easy Microwave Frosting where each stick and cookie are joined to ensure stability. Let dry about 30 minutes. Spread a thin layer of Easy Microwave Frosting on front side of each cookie, and sprinkle with desired decorations before frosting dries; then dry completely. Store in a cool, dry place.
Note: Do not substitute refrigerated cookie dough for this recipe. It contains leavening and tends to spread as it bakes, distorting cookie shapes.