1 (18.25 ounce) package yellow cake mix
⅔ cup of water
3 large eggs
½ cup butter softened
1 ⅓ cups packed brown sugar
1 tablespoon ground cinnamon, or to taste
1 tablespoon vanilla extract
1 ½ cups butter
4 ½ cups all-purpose flour
1 tablespoon confectioners’ sugar for dusting
Step 1: Prepare the oven and preheat to 175 degrees C or 350 degrees F.
Step 2: Apply cooking spray in a 12×18-inch jellyroll pan.
Step 3: In a medium mixing bowl, add water, yellow cake mix, 1/2 cup of melted butter, and eggs. Use an electric mixer to beat for 2 minutes or until well blended.
Step 4: Transfer the mixture into the greased jellyroll pan.
Step 5: Place inside the preheated oven and bake for 15 to 17 minutes or until the sides are brown and the centre is a little mushy.
Step 6: In a large mixing bowl, add cinnamon, brown sugar, flour, butter, and vanilla extract. Beat until well mixed.
Step 7: Remove the cake from the oven and let it sit on a wire rack.
Step 8: Add 3/4 of the crumb on top and press. Set aside the rest of the crumb.
Step 9: Put the cake back to the oven and bake for another 12 to 12 minutes or until the topping is set.
Step 10: Remove the cake from the oven and let it sit on a wire rack. Sprinkle the reserved crumb on top and allow the cake to cool at room temperature. Sprinkle confectioner’s sugar on top.
Step 11: Serve and enjoy!