Heat oven to 375°F. Coat 2 baking sheets with cooking spray.
Place 1 sheet phyllo on work surface. Keep remaining phyllo covered with plastic wrap. Brush sheet lightly with butter. Repeat with remaining phyllo, buttering each and stacking; leave top sheet unbuttered. Cut stacked sheets lengthwise into thirds, crosswise into sixths, for 18 rectangles. Place on baking sheets.
Bake in 375°F oven 8 to 10 minutes, until slightly colored. Remove with spatula to rack to cool.
For filling, beat cheese, sour cream, sugar substitute and vanilla in bowl until light and fluffy. Stir in jam.
Spread 1 rounded tablespoon filling over each of 12 phyllo rectangles. Arrange kiwi slices on 6 rectangles, halved raspberries on remaining 6.
Stack the raspberry rectangles on kiwi rectangles. Place a plain rectangle on top of each stack, for total of 6 Napoleons. Dust tops with powdered sugar.
Omit jam, kiwi, berries. Add 2 tablespoons mini chocolate chips in step 4. Drizzle tops with total of 2 tablespoons melted semisweet chocolate.
Omit jam, kiwi, berries. Add 1/4 teaspoon almond extract in step 4. Arrange drained mandarin orange segments from 15-ounce can on phyllo layers instead of kiwi and raspberries.