Preheat oven to 400 degrees F. Grease muffin cups or line with muffin liners.
TO MAKE BLUEBERRY MUFFINS: Combine 1½ cups flour, ¾ cup 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 blueberries.
Fill muffin cups right to the top and sprinkle with crumb topping mixture.
TO MAKE CRUMB TOPPING: Mix together ½ cup sugar, ⅓ cup flour, ¼ cup butter, and 1½ teaspoons cinnamon. Mix with fork, and sprinkle over muffins before baking.
Bake for 20 to 25 minutes, or until toothpick inserted in the center comes out clean.
Notes
Source: All Recipes
Recipe by Dallas Duo Bakes at http://dallasduobakes.com/2014/11/blueberry-crumb-muffins.html