Outrageously Buttery Crumb Cake

This simple crumb cake is the BEST I ever tasted. The cake is so moist, and there is a ton of buttery crumb topping to die for. It’s my aunt’s recipe from the 1970’s (hence the 1 pound of butter) and therefore of uttermost decadence, but oh so addictive! I’ve made this recipe so many times, with so many compliments. I basically eyeball the measurements now (I like a lot of cinnamon) but below is the original recipe.

Original recipe makes 1 12×18-inch sheet cake

Ingredients

1 (18.25 ounce) package yellow cake mix
2/3 cup water
3 eggs
1/2 cup butter, softened
1 1/3 cups packed brown sugar
1 tablespoon ground cinnamon, or to taste
1 tablespoon vanilla extract
1 1/2 cups butter
4 1/2 cups all-purpose flour
1 tablespoon confectioners’ sugar for dusting

PREP

15 mins
COOK

30 mins
READY IN

1 hr 45 mins

Directions

Preheat oven to 350 degrees F (175 degrees C). Grease a 12×18-inch jellyroll pan.
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.
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.
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. 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.
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.
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.