Ooh, I think I may have found it!
PEANUT BUTTER FONDANT
1 lb. confectioners' sugar
1/3 c. butter, softened
1/4 tsp. salt
1 tsp. vanilla
1/3 c. light corn syrup
Mix all ingredients until blended. Roll fondant between wax paper to 1/4 inch thickness. Spread with peanut butter. Roll the mixture in a "jelly roll fashion." Wrap in plastic wrap. Refrigerate 2 hours. Cut into slices with serrated knife.