1 1/2 cups flour
3/4 cup sugar
2 teaspoons baking powder
1/2 teaspoon salt
1/4 teaspoon ground cinnamon
1 large egg
1/2 cup whole milk
1/3 cup safflower or canola oil
1 cup fresh blueberries
For the streusel (makes a lot--cut in half if you don't like lots of streusel!)
2/3 cup flour
1/2 cup sugar
1/2 cup light brown sugar, packed
1 tablespoon ground cinnamon
1/8 teaspoon salt
1/2 cup (1 stick) butter, cubed
Preheat the oven to 400 F degrees. Line muffin tins with paper liners or spray them with nonstick baking spray.
In a large bowl, whisk together the flour, sugar, baking powder, salt, and cinnamon. In a separate bowl, whisk together the egg, milk, and oil. Make a well in the center of the flour mixture and add the wet ingredients, mixing until just combined. Fold in the blueberries. Using an ice cream scoop, fill the muffin cups almost to the top.
For the streusel topping, mix together all ingredients with your fingers, rubbing to make a coarse meal. Sprinkle the streusel over the muffins before baking, pressing lightly to adhere. Bake the muffins for 18-22 minutes or until a cake tester inserted comes out clean. Cool muffins in the pan for five minutes and then transfer to a wire rack to cool completely.