Grease the bottom and 1/2 inch up the sides of a 8″ or 9″ square baking pan.
Preheat your oven to 350 degrees Fahrenheit.
2 cups flour
2-1/2 teaspoons baking powder
1/4 teaspoon salt
1/2 cup cooking oil
3/4 cup sugar
1/2 cup milk
2 cups fresh or frozen blueberries
1/2 cup flour
1/2 cup sugar
1/2 teaspoon cinnamon
1/4 cup unsalted butter
Combine the 2 cups flour, salt and baking powder. Set aside.
In another bowl, pour your oil. Add the 3/4 cup sugar and blend well.
Beat in the egg.
Add the milk and flour mixture alternately. Make sure mixture is smooth after each addition before mixing more in.
Spoon that batter into the baking pan.
Sprinkle with the blueberries.
In a small bowl, combine the 1/2 cup flour, 1/2 cup sugar, and cinnamon.
Cut in the butter until it is crumbly.
Sprinkle the crumbles over the blueberries.
Bake in the preheated oven for 50-60 minutes or until the buckle is golden.