This recipe for sourdough blueberry muffins makes big, bakery style muffins that are tender and moist. They are baked to perfection with a crunchy, sweet crumb topping that is completely irresistible!
Crumb topping:Place the melted butter, flour and sugar in a bowl and use a fork to mix until it becomes a coarse crumble. Set aside.
Preheat the oven to 350°F (176°C). Line a 12 count muffin tin with paper liners or grease generously to prevent sticking.
Dry ingredients: In a large mixing bowl combine the flour, sugar, baking soda, baking powder, corn starch, lemon zest and salt with a fork. Add the blueberries and toss the mixture to coat. Set aside.
Wet ingredients: In a medium mixing bowl, whisk all the wet ingredients until smooth. Pour the wet ingredients into the dry ingredients and stir until just combined. (If the batter is too stiff, add 1-2 tablespoons of water or milk to help thin it down.)
Divide the batter evenly into 12 muffins and sprinkle the top with the crumble topping. Make sure to press the crumble, gently, on the top of the batter.
Bake for 30-35 minutes or until a toothpick inserted into the center of a muffin comes out clean. Let muffins cool in the tin for 10 minutes before removing to cool on a cooling rack.
Notes
Store the muffins loosely covered, at room temperature, for up to 3 days.
Freeze the muffins wrapped in plastic wrap, inserted into a freezer-safe bag for up to 3 months.