Preheat oven to 375 degrees. Prepare your muffin tins. 12 small cupcake tins with cupcake liners or 6 large cupcake tins with large liners. The liner should reach the top of the tin.
Start by creaming together softened butter, sugar and vanilla with a hand mixer in a large bowl.
Add 2 eggs and mix until well blended
Combine flour, salt, and baking powder. Blend together and then add to the large bowl creamed mixture alternately with the milk. I use a 1/4 cup measure to add the flour and then pour in a bit of milk after the flour is blended in.
Gently by hand fold in 1/2 cup blueberries. (2 1/2 cups is equivalent to 2 small packages of blueberries). After folding in the first 1/2 cup then gently fold in the remainder at approximately 1/2 cup at a time. Be gentle so that not to break the berries.
Using a large serving spoon, scoop the the batter into 6 lined cupcakes filling to the top of each. I prefer the large tins so that it's more like Mimi's Cafe. If using the larger tins then bake for 35 minutes or until browned on top. If using the smaller tins reduce the oven bake time to 25 minutes. Check middle of muffin with a toothpick. When the toothpick comes out clean the cake part is done. Try not to pierce a blueberry.
Let cool for 10-15 minutes to allow the berries to set.
My muffins were a little flat. When doing a Google it said to make sure your eggs and butter are at room temperature. Also not to let the batter sit too long before going in the oven. My eggs were straight from the fridge. Opps. Also, measuring by volume instead of weight will make the recipe off. I used volume so next time it's by weight for sure. The muffins are just beginning to rise in the oven here.