First, combine the flour, sugar, baking powder, and butter in a large bowl, and mix with a pastry blender. You will want to mix until the clumps are pea-sized. Take out 1 cup of this mixture and set aside.

Then add the eggs, milk, and vanilla extract. Gently whisk together. Since muffins are a quick bread and can ruin easily by too much stirring, you will want to stir until everything is just combined. There will be lumps, and that's okay. Once combined, gently fold in the blueberries and spoon into a greased muffin tin. This recipe will make about 2 dozen muffins.

Before you put the muffins in the oven, it needs the crunchy topping! Melt the extra tablespoon of butter and add it to the 1 cup of flour mixture you set aside earlier. Mix with a fork until the butter is fully combined. The mixture should be clumpy. Sprinkle the clumps on the muffins.

Bake in a 350° oven for 20-30 minutes. I start checking them at 20 minutes, and continue every 5 minutes or so until I can pull a toothpick out clean.