HEAT oven to 325ºF.
SPRINKLE 1 tsp. crumbs onto bottom of each of 12 paper-lined muffin cups.
BEAT cream cheese spread, cottage cheese, sugar replacement and vanilla in medium bowl with mixer until well blended. Add yogurt and cornstarch; mix well. Add egg; beat just until blended.
MIX 3/4 cup batter with melted chocolate. Pour remaining batter over crumbs; top with chocolate batter.
BAKE 26 to 30 min. or until centres are almost set. Cool 30 min. Refrigerate 3 hours. Top each mini cheesecake with 1 tsp. Cool Whip just before serving.