Combine flour, sugar, salt, cinnamon and baking powder
Place vegetable oil into a 1 cup measuring cup; add the egg and enough milk to fill the cup
Mix this with flour mixture
Add butter
Fold in blueberries
Fill muffin cups right to the top
Bake for 22 minutes in the preheated oven or until done
Notes:
I altered the original recipe because I never had good luck with the crumb topping. I just mixed the crumb topping ingredients into the muffin with better results.