Combine first 5 ingredients in a bowl; beat at medium speed of a mixer until smooth. Cover and chill.
Combine breadcrumbs, granulated sugar, and cinnamon in a bowl. Stir well, and set aside.
Preheat oven to 375°.
Place 1 phyllo sheet on a large cutting board or work surface; lightly brush with margarine. Sprinkle with 1 tablespoon breadcrumb mixture. Repeat layers with remaining phyllo, margarine, and breadcrumb mixture, ending with phyllo. Gently press phyllo layers together. Lightly coat top phyllo sheet with cooking spray. Cut 12 (3-inch) circles through phyllo layers using a sharp round cookie cutter. Carefully place layered circles on a baking sheet coated with cooking spray; discard any remaining phyllo scraps. Coat the bottom of another baking sheet with cooking spray; place, coated side down, on top of layered phyllo circles. Bake at 375° for 12 minutes or until crisp. Remove top baking sheet; place phyllo stacks on a wire rack. Cool completely.
Combine carambola, papaya, and banana; stir gently. Place 1 phyllo stack on each of 4 dessert plates. Spread about 1 tablespoon sour cream mixture on top of each stack; top each with about 3 tablespoons papaya mixture and 1 tablespoon sour cream mixture. For each serving, repeat layers with the remaining phyllo stacks, sour cream mixture, and papaya mixture, ending with phyllo stacks. Sprinkle powdered sugar over napoleons.