A big sheet cake that starts its life as a boxed cake mix gets a topping made of tons of buttery, crumbly streusel.
Preparation Time
15 mins
Cooking Time
30 mins
Total Time
45 mins
Calories
559 Calories
Recipe Instructions
Step 1
Preheat oven to 350 degrees F (175 degrees C). Grease a 12x18-inch jellyroll pan.
Step 2
Beat the yellow cake mix, water, eggs, and 1/2 cup softened butter together with an electric mixer in a mixing bowl until thoroughly blended, about 2 minutes on medium speed. Pour the cake batter into the prepared jellyroll pan.
Step 3
Bake in the preheated oven until the edges of the cake are light brown but the middle of the cake is still slightly gooey, 15 to 17 minutes.
Step 4
Return the cake to the oven, and bake an additional 10 to 12 minutes, until the crumb topping is firm and the cake is cooked all the way through.
Step 5
Gather all ingredients.
Step 6
While the cake is baking, mix together the brown sugar, cinnamon, vanilla extract, butter, and flour together in a large bowl until the mixture forms medium crumbs.
Step 7
Remove the cake from the oven, and press about 3/4 of the crumb topping onto the top of the almost-baked cake. Reserve the remaining topping.
Step 8
Remove the cake from the oven, and sprinkle with the remaining crumb topping. Let the cake cool to room temperature, and sprinkle with confectioners' sugar.