Best Ever Blueberry Muffins

Preheat oven to 400 degrees. Grease muffin cups or line with muffin liners. Combine 1-1/2 cups flour, 3/4 c. sugar, salt and baking powder. Place vegetable oil into a 1 cup measring cup; add the egg and enough milk to fill the cup. Mix this with the flour mixture. Fold in blueberries. Fill muffin cups right to the top, and sprinkle with crumb topping mixture. To make crumb topping: Mix together 1/2 c. sugar, 1/3 c. flourj, 1/4 c. butter and 1-1/2 tsp. cinnamon. Mix with fork, and sprinkle over muffins before baking. Bake for 20-25 mins. or until toothpick tester comes out clean.