To Die for Blueberry Muffins

1.5 Cups all purpose flour
3/4 cup white sugar
1/2 tsp salt
2 tsp baking powder
1/3 cup vegetable oil
1 egg
1/3 cup milk
1 cup fresh blueberries
Crumble Topping
1/2 cup white sugar
1/3 cup all purpose flour
1/4 cup butter-cubed
1.5 tsp ground cinnamon
Preheat oven to 400 degrees F. Grease muffin cups.
Combine dry ingredients. Place vegetable oil into a 1 cup measuring cup; add the egg and enough milk to fill the cup. Mix this with flour mixture. Fill muffin tins 2/3 full.
For topping, mix ingredients with fork and sprinkle over muffins. Bake for 20-25 minutes, or until done.