Preheat the oven to 375℉. Line a muffin tin with 12 liners and set aside. If using tulip liners, line the tin with 8 tulip liners.
In a large bowl, add in the dry ingredients; flour, white sugar and baking powder. Mix together.
3/4 cups white sugar, 1 1/2 cups all purpose flour, 1 3/4 tsp baking powder
Add in about 1/3 of the butter. Mix on low, and then add the next 1/3 cup and keep adding in the butter until a crumbly texture forms. The key to these muffins is mixing as little as possible, so only mix each addition in until just combined!
3/4 cup unsalted butter
Add the eggs and egg yolk in one at a time, mixing on low speed in between each addition. Then mix in the vanilla. On low speed, keep mixing until just combined.
1 tbsp vanilla extract, 1 large egg yolk, 2 large eggs
Add in the milk, and mix in well. The batter will be very smooth at this point.
1/3 cup milk
In the bowl with the blueberries, add 1-2 tsps of flour and gently toss around until evenly coated.
1 1/2 cups fresh blueberries
Add the blueberries into the bowl and mix in a few times with a spatula. Don't over-mix!
Evenly divide the batter between the muffin liners. Sprinkle white sugar and a few extra blueberries on top.
Bake the muffins for 17-20 minutes if you're using regular liners, and 20-25 minutes if using tulip liners. A toothpick inserted in the middle will come out clean.
Cool, and enjoy! These muffins are the best.