Prepare the Cake: Cut the cooled angel food cake into 1-inch cubes.
Layer the Ingredients: In a 9×9 inch cake pan, layer half of the cake cubes evenly on the bottom. Spread ⅔ of the cherry pie filling over the cake layer, then top with the remaining cake cubes.
Make the Pudding: In a medium bowl, whisk together the instant vanilla pudding mix, milk, and sour cream until smooth. Spread the pudding mixture evenly over the top of the cake.
Top with Cool Whip and Cherries: Spread the Cool Whip evenly over the pudding layer. Spoon the remaining cherry pie filling over the Cool Whip.
Chill: Refrigerate the cake for 4-5 hours, or until chilled and set.
Serve: Garnish with sliced almonds, if desired, and serve chilled.