Heat oven to 350 degrees F.
Mix sugar and butter in medium bowl; stir in pineapple and nuts. Place cherry half, cut-side up, in center of each of 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 racks. Cool completely. Remove paper liners just before serving; invert onto plates.