Preheat oven to 400°F.
Prepare streusel topping by combining flour, brown sugar, and melted butter in a bowl. Set it aside.
In a large bowl, combine fresh milled flour, sugar, baking powder, and salt. Stir together and add blueberries
In another bowl, combine milk, oil, and egg. Combine.
Pour wet ingredients into the dry and stir together until just combined.
Fill muffin tin with batter until almost full. Using your hands, add streusel topping to each muffin.
Bake at 400°F for 10 minutes and then drop the temperature to 375° for an additional 15-20 minutes.
Cool and enjoy.
Notes: Do not thaw blueberries if using frozen. Using muffin liners makes for easier removal from the pan.