Step 1

Heat oven to 350°F. Spray 13x9-inch pan with cooking spray.

Step 2

Make and bake cake as directed on box, using water, butter and eggs and adding cinnamon and vanilla.

Step 3

While cake is baking, in small bowl, mix Cereal Crumble ingredients. Spread in ungreased shallow baking pan; set aside.

Step 4

Remove cake from oven to cooling rack; cool 5 minutes. Place cereal crumble in oven; bake at 350°F for 7 minutes. When baked, remove from pan to paper towels or flat paper bag.

Step 5

When cake has cooled 5 minutes, with handle of wooden spoon (1/4 to 1/2 inch in diameter), poke holes almost to bottom of cake every 1/2 inch, wiping spoon handle occasionally to reduce sticking.

Step 6

In medium bowl, stir together Filling ingredients (mixture will thicken). Pour over cake; spread evenly over surface, working back and forth to fill holes. (Some filling should remain on top of cake.) Refrigerate 1 hour.

Step 7

Spread whipped topping evenly over cake. Immediately before serving, sprinkle crumble over top.