• Begin by preheating your oven to 400 degrees F (200 degrees C). Prepare 8 muffin cups by either greasing them or lining them with paper liners.

To Make the Muffins:

• In a large mixing bowl, whisk together the all-purpose flour, white sugar, baking powder, and salt until well combined.
• In a small liquid measuring cup, pour in the vegetable oil. Crack the egg into the cup and then add enough milk to reach the 1-cup mark. Stir the mixture until it's well blended. Pour this liquid mixture into the bowl with the dry ingredients and mix until the batter is just combined. Gently fold in the fresh blueberries. Set the batter aside while you prepare the crumb topping.

To Make the Crumb Topping:

• In a small bowl, combine the white sugar, all-purpose flour, cubed butter, and ground cinnamon. Use a fork to mix the ingredients until the mixture becomes crumbly.
• Spoon the muffin batter into the prepared muffin cups, filling them to the top. Sprinkle the crumb topping evenly over each muffin.
• Place the muffin tray in the preheated oven and bake for 20 to 25 minutes, or until a toothpick inserted into the center of a muffin comes out clean. Enjoy these delicious blueberry muffins warm from the oven.