In a medium mixing bowl, whisk together the vanilla pudding, milk, and sour cream until smooth and it begins to thicken. Set aside.
1 (3.4oz) box instant vanilla pudding, 1½ cups whole milk, 1 cup sour cream
Cut the angel food cake into 1-inch cubes and then evenly layer half of it into the bottom of the baking pan.
14 ounces angel food cake
Spread about ⅔ of the pie filling on top of the cake and then layer the remaining angel food cake over it.
1 (21 oz) can blueberry pie filling
Evenly spread all of the vanilla pudding mixture over the cake layer and then top it with the Cool Whip. Make sure to spread them over the top of the entire cake.
8 ounce Cool Whip
Drop spoonfuls of the remaining pie filling over the cake. You can use a butter knife or a skewer to swirl the pie filling around. Try to make sure each slice will get a good amount.
1 (21 oz) can blueberry pie filling
Place in the refrigerator uncovered to chill for 4 to 6 hours or overnight. Refrigerating it will help the layers to set and let the flavors develop.
Right before serving, sprinkle with slivered almonds.
3 tablespoons almond slivers