FOR THE CAKE:
1 1/2 cups all-purpose flour
1/2 cup granulated sugar
1-1/2 tsp. baking powder
1/2 tsp. salt
1 large egg
1/2 cup milk (or buttermilk for more moistness)
2 Tbsp. canola oil
2 tsp. vanilla extract
FOR THE CRUMBLE TOPPING:
2 1/2 cups all-purpose flour
1 cup light-brown sugar
1-1/2 tsp. cinnamon
1 cup (2 sticks) butter, melted and cooled
Confectioner's sugar for dusting
Preheat oven to 350F degrees.
Spray an 8x8 baking dish with nonstick cooking spray. (For a thinner cake, use a 9x13 baking dish)
In a medium bowl combine 1 1/2 cups flour, sugar, baking powder and salt.
Stir until combined.
In another bowl, combine egg, milk, oil and vanilla extract. Stir until it's all combined.
Combine flour mixture with milk mixture and mix well.
Pour the batter into your prepared baking dish.
Now to make the crumble topping.
In a medium bowl, combine brown sugar, flour and cinnamon. Mix it together.
Then pour in melted butter and stir until combined and clumps begin to form.
Sprinkle those clumps (crumbs) all over the cake batter. If you are using an 8x8 dish it will be thick.
Bake for about 30 minutes for an 8x8 dish. Bake for about 20 minutes for a 9x13 baking dish.
Use a toothpick to check for doneness.
Crumb topping should be golden brown and a toothpick inserted to the middle of the cake should come out clean.
Allow cake to cool. Then dust with a bit of powdered sugar. Use a serrated knife to cut into slices.