Bakery-Style blueberry Muffins

Ingredients

• Crumb Topping — 1/2 cup (60g) all-purpose flour
• Crumb Topping — 2 tablespoons cornstarch
• Crumb Topping — 1/4 cup (52g) light brown sugar
• Crumb Topping — 1/4 cup (50g) granulated sugar
• Crumb Topping — 6 tablespoons (90g) salted butter, melted
• Crumb Topping — Muffins
• Crumb Topping — 1/2 cup (115g) unsalted butter, melted
• Crumb Topping — 1 cup (200g) granulated sugar
• Crumb Topping — 2 teaspoons baking powder
• Crumb Topping — 1/2 teaspoon baking soda
• Crumb Topping — Pinch of salt
• Crumb Topping — 1 tablespoon vanilla bean paste or vanilla extract
• Crumb Topping — 2 1/2 cups (315g) all-purpose flour
• Crumb Topping — 2 eggs, room temperature
• Crumb Topping — 1 1/2 cups blueberries
• Crumb Topping — 1 cup buttermilk, room temperature (see note)
• Crumb Topping — 1/4 cup (65g) sour cream, room temperature (see note)
• Crumb Topping — 2 tablespoons neutral oil

Instructions

1. Preheat the oven to 425°F (220°C). Prepare the baking tin by lining or greasing it.
2. In a mixing bowl, whisk together the melted butter and sugar until well combined.
3. Add the eggs and whisk for 2-3 minutes or until pale in color.
4. Add the milk mixture, vanilla extract, sour cream, and oil. Mix until well combined.
5. In a separate bowl, combine the dry ingredients: flour, baking powder, baking soda, and salt. Reserve 2 tablespoons of the dry mixture to coat the blueberries.
6. Pour the wet mixture into the dry ingredients and mix until just combined.
7. Toss the blueberries in the reserved 2 tablespoons of dry mixture.
8. Add the blueberries to the batter.
9. Do not overmix the batter.
10. Let the batter sit at room temperature for 30 minutes.
11. Do not mix the batter again.
12. Make the crumb topping: In a bowl, mix melted butter, granulated sugar, and brown sugar. Mix until a paste forms, then add all-purpose flour and cornstarch. Mix until crumbly and coarse.
13. Divide the batter evenly among the muffin cups.
14. Bake for 5 minutes, then reduce the oven temperature to 375°F (190°C) without opening the oven door. Continue baking for an additional 15 minutes or until a toothpick inserted in the center comes out clean.