- Vanilla Pudding: Pour milk into large bowl. Using electric mixer at low speed, blend in vanilla pudding mix for about 1 minute to make a lump-free slurry. Scrape down sides and bottom ofs bowl. Continue to mix at low speed for 5 to 7 minutes. Refrigerate for 10 to 15 minute before using.
- Creamy Topping Layer: In medium bowl, stir together whipped topping and sour cream until blended.
- Cake: Halve sheet cake lengthwise. Trim each half so that it fits into the bottom a full hotel pan (approx. 40 x 23 cm/16 x 9 inches). Set halves aside and reserve trimmings.
- Assembly: Set aside 500 mL (2 cups) cherry pie filling. Spread remaining cherry pie filling in bottom of full hotel pan. Top with 1 cake half; use some of the trimmings to fill in gaps.
- Spoon half of the vanilla pudding over top; spread in an even layer. Spoon half the creamy topping over pudding; spread in an even layer. Repeat with second cake half, more trimmings to fill gaps, remaining pudding and remaining creamy topping.
- Add dollops of reserved cherry pie filling over top of cake; swirl with back of spoon. Sprinkle with granola. Refrigerate for at least 2 hours before serving.
- Cut or scoop into twenty-five 250 mL (1 cup) servings.
Tip: If desired, substitute cherry pie filling with blueberry, apple or peach pie filling. Or substitute the white or vanilla sheet cake with chocolate sheet cake to create a Black Forest–themed cake.
