Preheat the oven to 350F and line a muffin pan with liners.
Make the streusel topping:
In a bowl, combine the flour and sugar. Melt the butter and mix it with the dry ingredients. Using your hands, mix it to give it the texture of coarse sand. Sometimes I pinch with my fingers to create the clumps. Set aside.
Make the muffin batter:
In a large bowl, combine the flour, baking powder, soda, and salt. Mix well with a whisk to distribute the ingredients.
In a large bowl with a hand mixer or your stand mixer, beat the butter and sugar until it's light and airy, for about 5 minutes, using a spatula to scrape down the sides of the bowl when necessary.
Add the eggs, one at a time, and beat until combined. Add the vanilla extract and the yogurt and stir just until the yogurt is mixed in, being careful not to overmix.
Combine the wet and dry ingredients in the bowl. Use a fork or a rubber spatula to stir the mixture just until the dry ingredients are combined. The batter will be thick. Fold the blueberries into the batter.
Fill the muffin pan:
Use a big tablespoon to fill the muffin tins nearly to the top. Sprinkle a little of the topping on each muffin and then make a second pass to distribute the rest, gently pressing the streusel topping down so the crumbs stay on the muffin when they rise during baking.
Bake:
Bake the muffins for 20 to 22 minutes, until the tops are golden and a toothpick comes out clean when inserted in the middle. Remove the muffin pan from the oven and let the muffins cool completely before taking them out.
Store:
Muffins can be stored in an airtight container at room temperature (on the counter) for 1 day, in the refrigerator for up to 5 days, or in the freezer for up to 3 months.
Notes
I have also successfully made these muffins with Bob’s 1:1 gluten-free baking flour.