1In a mixing bowl, whisk together the melted butter and granulated sugar until well combined.
2Add the eggs and whisk for 2-3 minutes or until pale in color.
3Add the milk mixture, vanilla extract, sour cream, and oil. Mix until well combined.
4In 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.
5Toss the blueberries in the reserved 2 tablespoons of dry mixture.
6Pour the wet mixture into the dry ingredients and mix until just combined.
7Add the blueberries to the batter. Do not overmix the batter.
8Let the batter sit at room temperature for 30 minutes. Do not mix the batter again.
9Make 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.
10Divide the batter evenly among the muffin cups.
11Add the crumble on top of each muffin.
Ingredients
60 g all-purpose flour
2 tablespoons cornstarch
52 g light brown sugar
50 g granulated sugar
90 g salted butter
115 g unsalted butter
200 g granulated sugar
2 teaspoons baking powder
0.5 teaspoon baking soda
1 pinch salt
1 tablespoon vanilla bean paste or vanilla extract
315 g all-purpose flour
2 eggs
1.5 cups blueberries
1 cup buttermilk
65 g sour cream
2 tablespoons neutral oil
Equipment
mixing bowlwhiskmuffin tinwire rack
Tips
To make your own buttermilk at home, mix 1 cup of milk with 1 tablespoon of white vinegar or lemon juice. Let it sit for 5-10 minutes before using.
You can substitute sour cream with Greek yogurt if you prefer. This will give your muffins a slightly tangier flavor and a moist texture.