1. Preheat oven to 350 degrees.
2. Combine flour, sugar, salt 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. Fold in fruit. Fill muffin cups right to the top, and sprinkle with crumb topping mixture.
3. To Make Crumb Topping: Mix together sugar, flour, butter, and cinnamon. Mix with fork, and sprinkle over muffins before baking.
4. Bake for 30 to 35 minutes in the preheated oven, or until done.