Preheat the oven to 400 degrees.
Line 12 to 15 muffin cups with liners. If you don’t have cupcake wrappers, you can simply spray the muffin cups with cooking spray.
First, you will create the crumb topping for the muffins.
In a small bowl, melt the butter by microwaving it for 20 to 30 seconds.
Using a fork, stir in the flour and the sugar for the crumb topping. This mixture will be crumbly. Set it aside until you need it later.
In a medium bowl, stir together the flour, baking powder, sugar, and salt.
In a separate smaller bowl, mix together the eggs, yogurt, oil, and vanilla until they are fully combined.
Working quickly, stir the wet ingredients into the bowl full of dry ingredients.
Don’t over mix the batter. Leaving a few lumps is fine. The batter will be rather thick, almost like a brownie batter.
Using a rubber spatula, fold in all but about a half cup of the blueberries. Gently flip the batter to incorporate all of the berries.
Spoon the batter into the prepared muffin cups, filling them about ⅔ of the way full.
Take the reserved berries and scatter them on top of the muffin batter.
Divide the crumb topping between the muffin cups, sprinkling it on top of the uncooked batter and the blueberries.
Bake the blueberry muffins in the center of the oven heated to 400 degrees for about five minutes.
Reduce the heat to 375 degrees, and bake for about 15 minutes, or until the center of each muffin springs back when lightly touched.
Remove the muffins from the oven and allow them to cool in the pan for about five minutes.
Then, take the muffins out of the pan and let them cool on a wire rack for about 20 minutes before serving.
To store, place the muffins in an airtight container and store at room temperature for up to five days. If you like, you can place extra muffins in the freezer in a zip top storage bag, with as much air pressed out of the bag as possible.
Thaw the frozen muffins by microwaving them on a paper napkin for about 30 seconds.