MIX: sugar and butter in medium bowl; stir in pineapple tidbits and nuts. Place cherry half, cut side up, in center of each 24 paper-lined muffin cups. Cover with pineapple mixture.
ADD: boiling water to gelatin mix; stir 2 minutes until completely dissolved. Cool 10 minutes.
BEAT: remaining ingredients in large bowl with mixer until well blended. Add gelatin; mix well. Spoon over pineapple mixture in muffin cups. (Cups will be almost completely filled.)
BAKE: 15 to 18 minutes or until toothpick inserted in centers comes out clean. Cool in pans 10 minutes; remove from pans to wire cooling racks. Cool completely. Remove paper liners just before serving.