1-Preheat the oven to 425°F. Grease the entire standard-size muffin pan including the rim with butter or non-stick spray to prevent sticking.

2-In a small bowl, mix 1/4 cup (50g) granulated sugar, 1 tablespoon all-purpose flour, and 1/8 teaspoon ground cinnamon for the streusel topping. Stir in 2 teaspoons unsalted butter, melted, and set aside.

3-In a large bowl, whisk together 2 1/2 cups (315g) all-purpose flour, 1 tablespoon baking powder, 1 teaspoon baking soda, and 1/2 teaspoon salt.

4-In a separate bowl, whisk 1/2 cup (114g) melted and cooled unsalted butter with 1 cup (200g) granulated sugar until combined. Add 2 large eggs, 1 cup (240ml) milk of choice, and 1 tablespoon vanilla extract, then mix well.

5-Add the wet ingredients to the dry ingredients and gently stir with a rubber spatula until almost combined. Fold in 1 1/2 cups (230g) blueberries just until mixed.

6-Divide the batter into 12 muffin cups, filling each to the top. Sprinkle the streusel topping evenly over the muffin batter.

7-Bake at 425°F for 5 minutes, then lower the temperature to 375°F without removing the muffins, and bake for an additional 15 minutes or until a toothpick inserted comes out clean.

8-Let the muffins cool in the pan for 10 minutes, then transfer to a wire rack.