Here’s the recipe.
Set rack in the middle of the oven and preheat to 375 degrees. Get one 12-cavity muffin pan ready with paper liners.
Crumb Topping
1 cup all-purpose flour, 1/2 tsp. baking powder, 1/4 tsp. ground cinnamon, 6 tbsp. unsalted butter, 1/2 cup light brown sugar.
Combine flour, baking powder, and cinnamon in a medium mixing bowl and stir well to mix. Melt the butter in a small pan. Remove from heat, then add the brown sugar to the pan of melted butter and use a small heatproof spatula to stir them together. Scrape the butter and sugar mixture into the flour mixture, stirring it in until the flour is evenly moistened. Set aside while preparing the muffin mixture.
Muffin Batter
2 1/2 cups all-purpose flour, 2 tsp. baking powder, 1/4 tsp. salt, 1/4 tsp. freshly ground nutmeg, 8 tbsp. (1 stick) softened unsalted butter, 3/4 cup sugar, 1/2 cup light brown sugar, 2 large eggs, 1/2 cup milk, 1 pint of blueberries that have been rinsed, drained, and picked over.
Combine the flour, baking powder, salt, and nutmeg in a mixing bowl and stir well to mix.
Combine the butter and sugars in the bowl of an electric mixer fitted with the paddle attachment. Beat on medium speed for about 1 minute, or until well mixed and a little lightened in color. Beat in the eggs one at a time, beating smooth after each.
Decrease the mixer speed to low and beat in 1/2 the flour mixture. Stop the mixer and use a large rubber spatula to scrape down the bowl and beater.
On low speed, beat in the milk. After the batter has absorbed the milk, beat in the remaining flour mixture. Stop and scrape down the bowl and beater again.
Add the blueberries to the bowl and beat them into the batter on the lowest speed for no more than 2-3 seconds, to crush some of the berries slightly.
Remove the bowl from the mixer and use a large rubber spatula to give a final mixing to the batter.
Divide batter equally among the cavities in the muffin pan. Break the crumb topping into small crumbs with your fingertips and scatter over the top of each muffin. (At this point, I personally mounded the crumb topping on because there was so much of it! If you don’t like a sweet topping, stick to the scatter) Bake the muffins until they are well risen, feel firm to the touch, and the topping is golden, about 30 minutes. Cool the muffins in the pan on a rack.
