In a small bowl, combine cookies and butter. Press onto the bottom of a 9-in. springform pan coated with cooking spray. Place pan on a baking sheet. Bake at 350° for 8-10 minutes or until set. Cool on a wire rack.
Drain cherries, reserving syrup. Cover and refrigerate syrup. Chop half of the cherries; refrigerate whole cherries. Spread frozen yogurt evenly over crust; sprinkle with chopped cherries. Cover and freeze for 30 minutes. Spread ice cream over cherries; cover and freeze for 2 hours or until firm.
For sauce, in a small saucepan, combine cornstarch and reserved cherry syrup until smooth. Bring to a boil; cook and stir for 2 minutes or until thickened. Remove from the heat; stir in lemon juice and whole cherries.
Remove sides of springform pan; cut dessert into slices. Serve with sauce. Garnish with whipped topping and mint. Yield: 12 servings.