Bake Blueberry Muffins with a crunchy crumb topping — moist, quick, and perfect for breakfast or brunch.
Warm up the oven to 375°F and prepare a standard-size muffin tin: line each cup with paper liners or grease generously with non-stick spray. Doing this first keeps the workflow smooth and ensures the muffins release easily after baking. If you like tidy tops, use liners; if you prefer a crisper base, grease the tin well. Set the prepared tin nearby on the painted white pine surface so it’s ready when the batter is mixed.
In a large mixing bowl, whisk together the all-purpose flour, granulated sugar, salt, baking soda, and baking powder until evenly distributed and aerated. This step builds the structure for the muffins; taking a moment to break up the sugar and evenly distribute leavening gives more consistent rise. Keep the bowl and whisk or spoon handy on the work surface for the next step.
Make a well in the dry mixture and pour in the oil, add the egg, buttermilk, and vanilla. Gently stir just until the dry ingredients are moistened — don’t overmix; a few small streaks of flour or a slightly lumpy batter is perfect. Lightly toss the blueberries in a spoonful of flour to help prevent sinking, then gently fold the berries into the batter with a spatula until evenly distributed. Spoon or portion the batter into the prepared muffin cups, filling them nearly full so the tops will dome nicely on baking.

Combine the granulated sugar, light brown sugar, flour, and ground cinnamon in a small bowl. Cut the cold, chopped butter into the dry mix using a fork or pastry blender until the mixture resembles coarse crumbs and the butter is pea-sized. The cold butter creates that desirable crunchy, sugary streusel as it melts in the oven.
Generously sprinkle the crumb topping over each filled muffin cup so each top will have an even, crunchy crust. A light press to help the crumbs adhere is fine, but don’t compress the batter. The contrast between the tender interior and sugary streusel will be noticeable after baking.
Bake the muffins for 17–20 minutes, or until a toothpick into the center comes out clean or with just a few moist crumbs. Remove the tin from the oven and allow the muffins to cool in the pan for a few minutes, then transfer to a wire rack to cool completely. Once cooled, arrange the muffins for serving — the tops should be golden-brown, domed, with speckled blueberries and a crisp, sugary crumb.
