Preheat oven to 350°F with a rack in the center. Line a standard muffin pan with paper liners. If your pan isn't unimpeachably nonstick, it's wise to spray the top with nonstick spray or rub it with a little bit of oil before baking, especially if you're making 12 muffins, since they'll rise up around the edges of the cups.
In a medium bowl, stir together the 2 cups flour, baking powder, baking soda, and ½ teaspoon salt.
In a small bowl, stir together the yogurt and vanilla extract.
In the bowl of a stand mixer fitted with the paddle (or a large mixing bowl with electric beaters), beat together the 4 tablespoons butter and the 1 cup sugar until lightened in color and texture, about 3 minutes.
Add the eggs and beat to incorporate.
Add half the flour mixture and beat on low until just incorporated.
Follow with half the yogurt mixture, again beating on low until just incorporated.
One by one, mix in the remaining halves of the flour and yogurt, beating on low after each addition.
Fold blueberries into the batter.
Divide among muffin cups.
To make the crumble topping, stir together the flour, brown sugar, nuts, cinnamon and salt in a small bowl.
Pour the melted butter overtop and stir to incorporate into the dry ingredients.
Cover the surface of each muffin with topping and press lightly.
Bake for about 24 minutes, until a tester comes out almost clean.
Let muffins cool for five minutes in the pan and then remove to a wire rack to cool completely.