Heat oven to 350°F. In medium bowl, mix all crust ingredients with fork until crumbly. Press in bottom of ungreased 13x9-inch pan. Bake 10 minutes.
Meanwhile, in large bowl, beat all filling ingredients with wire whisk or electric mixer on medium speed until blended. Pour over partially baked crust.
Bake 55 to 60 minutes or until set and knife inserted in center comes out clean. Cool completely, about 40 minutes.
In chilled small bowl, beat whipping cream and powdered sugar with electric mixer on high speed until soft peaks form. Cut dessert into squares. Serve with whipped cream. Garnish each serving with candy pumpkin.