Preheat oven to 425°F. Remove one crust from pouch. Place on a cutting board or flat surface and roll out lightly to a 10-inch diameter. Using a 4-inch round cutter, cut out six rounds. Set scraps aside. Repeat with second crust.
Lightly press the pastry rounds into 12 muffin cups pressing into bottom and up sides to create pastry cups. Prick cups with a fork and bake for 5 minutes.
In a medium bowl, mix together the cherry pie filling and the sweetener. Gently fold in the raspberries. Spoon about 3 tablespoons of the filling into each crust-lined cup.
Bake for 18 to 20 minutes, or until the edges and sides of the cups are browned, and the filling is bubbly. Let cool slightly and serve warm or cool. Garnish each pie cup with a dollop of topping if desired.