Perfect Blueberry Muffins

I could not possibly love these muffins more.  They're perfectly moist with a delicious crumb topping.  And they are so easy to make!  Just plop a bunch of ingredients together and voila!  I've messed with this recipe so many times (sometimes I'll use whole wheat flour, sometimes I'll substitute brown sugar, etc.) and I'm fairly certain it is impossible to mess up these muffins.  So without further ado...

Found this recipe on AllRecipes.com

Blueberry Streusel Muffins

Ingredients

(For crumb topping)
1/2 cup white sugar
1/3 cup all-purpose flour
1/4 cup butter, room temp
1 1/2 teaspoons ground cinnamon

(For muffins)
1-1/2 cups all-purpose flour
3/4 cup white sugar
1/2 teaspoon salt
2 teaspoons baking powder
1/3 cup vegetable oil
1 egg
Milk (approx 1/3 cup)
1 cup fresh or frozen blueberries

Directions
1. Preheat oven to 400 degrees F and line muffin pan with liners.
2. Crumb Topping: Mix together 1/2 cup sugar, 1/3 cup flour, 1/4 cup butter, and 1 1/2 teaspoons cinnamon. Mix with fork (do not overmix); set aside
3. Combine 1 1/2 cups flour, 3/4 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 to the top, and sprinkle with crumb topping mixture.
4. Bake for 20 to 25 minutes.