Use a serrated knife to cut the angel food cake into 1-inch square chunks.
Using a deep dish 8x8 square baking dish, evenly layer half of the angel food cake chunks into the bottom of the pan. Spread half of the cherry pie filling over the angle food cake.Place the remaining angel food cake chunks into an even layer over the cherry pie filling. * If you don't have a deep dish 8x8 baking pan then use a regular 9x9 baking pan instead. Pyrex makes a deep dish, clear glass 8x8 baking dish.
In a mixing bowl, add the dry instant vanilla pudding mix, whole milk, and sour cream. Stir with a wire whisk, for 1-2 minutes, until it's thoroughly combined, smooth, and thick. * Let it sit for a few minutes to thicken up, before using, if needed. It should thicken up fairly quickly because of the sour cream and whole milk fat.
Spread the pudding mixture over top the angel food cake layer. Spread the Cool Whip into an even layer over top the pudding. Swirl the remaining cherry pie filling over top. * To swirl : Dollop the pie filling over top the Cool Whip. Use a toothpick or spoon to gently swirl it around into the desired pattern.
Cover the cake with plastic wrap, foil, or a lid. Let it refrigerate for at least 8 hours, or overnight (12-16 hours), works best.
Sprinkle the sliced almonds over top the cake before serving.
