Ingredients
For the Muffins:
2 cups (240g) all-purpose flour
½ cup (100g) granulated sugar
2 teaspoons baking powder
½ teaspoon baking soda
¼ teaspoon salt
1 large egg, room temperature
1 cup (240ml) buttermilk or milk (see notes for substitution)
½ cup (120ml) vegetable oil or melted unsalted butter
1 teaspoon vanilla extract
1 ½ cups fresh or frozen blueberries (do not thaw if frozen)
For the Crumble Topping:
½ cup (60g) all-purpose flour
¼ cup (50g) granulated sugar
¼ cup (50g) packed light brown sugar
¼ teaspoon ground cinnamon (optional)
4 tablespoons (56g) unsalted butter, cold and cubed
Instructions
Preheat your oven to 400°F (200°C). Line a 12-cup muffin tin with paper liners or grease generously.
Prepare the Crumble Topping: In a medium bowl, combine the flour, granulated sugar, brown sugar, and optional cinnamon. Add the cold, cubed butter. Use your fingertips or a pastry blender to cut the butter into the dry ingredients until the mixture resembles coarse crumbs with some pea-sized pieces remaining. Set aside.
Prepare the Muffin Batter: In a large bowl, whisk together the all-purpose flour, granulated sugar, baking powder, baking soda, and salt. Make a well in the center of the dry ingredients.
In a separate medium bowl, whisk together the egg, buttermilk (or milk), vegetable oil (or melted butter), and vanilla extract until well combined.
Pour the wet ingredients into the well in the dry ingredients. Stir with a spoon or spatula just until the dry ingredients are moistened and no streaks of flour remain. Be careful not to overmix; a few lumps are perfectly fine. Overmixing leads to tough muffins.
Gently fold in the blueberries. If using frozen blueberries, do not thaw them; toss them lightly with a tablespoon of flour from the measured amount before adding them to the batter to prevent them from sinking.
Divide the muffin batter evenly among the 12 prepared muffin cups, filling each about two-thirds full.
Generously sprinkle the prepared crumble topping over the top of each muffin.
Bake the Muffins: Place the muffin tin in the preheated oven. Bake at 400°F (200°C) for 5 minutes. This initial high heat helps create a nice dome on the muffins.
After 5 minutes, reduce the oven temperature to 375°F (190°C) and continue baking for another 15-18 minutes, or until the muffins are golden brown, a wooden skewer or toothpick inserted into the center comes out clean (or with a few moist crumbs attached), and the tops spring back when lightly touched.
Remove the muffins from the oven and let them cool in the muffin tin for 5 minutes before carefully transferring them to a wire rack to cool completely.
Serve warm or at room temperature and enjoy!