PREPARATION:

1. Preheat oven to 350°F. Grease cookie sheets. For buns, remove dough from wrapper; place in large bowl. Let dough stand at room temperature about 15 minutes.
2. Add peanut butter, flour, brown sugar and vanilla to dough in bowl; beat at medium speed of electric mixer until well blended. Shape into 48 (1-inch) balls; place 2 inches apart on prepared cookie sheets.
3. Bake 14 minutes or until lightly browned. If desired, remove cookies from oven after 10 minutes; brush half of cookies with egg white and sprinkle with sesame seeds, if desired. Return to oven 4 minutes to finish baking and brown sesame seeds. Remove from oven. Cool on cookie sheets 2 to 3 minutes. Remove to wire racks; cool completely.
4. For burgers, remove 1/2 package of dough from wrapper. Beat dough, cocoa, brown sugar and vanilla in large bowl at medium speed of electric mixer until well blended. Shape into 24 (1-inch) balls; place 2 inches apart on prepared cookie sheets. Flatten cookies with tines of fork to a 1/4-inch thickness with a diameter slightly larger than buns.
5. Bake 12 minutes or until firm. Cool on cookie sheets 2 to 3 minutes. Remove to wire racks; cool completely.
6. To assemble, use icing to attach burgers to flat sides of 24 buns; pipe red, yellow and green icings on burgers. Top with remaining buns.