1
Heat the oven to 200°C and prepare 8 cups of a muffin tray by greasing them or lining them with paper liners.
2
Combine the flour, sugar, baking powder, and salt in a large bowl and whisk together.
3
Separately, add vegetable oil, the egg and milk and stir the together until well combined.
4
Add the wet mixture to the flour mixture, stirring until just combined. Gently fold in the blueberries, then set the batter aside.
5
Prepare the crumb topping by mixing sugar, flour, butter, and cinnamon in a small bowl. Use a fork to combine until the mixture is crumbly.
6
Fill the prepared muffin cups with the batter to the top and then add the crumb topping on top.
7
Bake until a toothpick inserted into the center of a muffin emerges clean, which takes about 20 to 25 minutes.