Dust 2 cups of blueberries with some flour. This helps them not sink to the bottom of the pan.
In the bowl of your stand mixer fitted with the paddle tool, beat together butter + sugar until well combined on medium-low speed. Do not over mix we want to do minimal mixing throughout this whole recipe.
Add room temperature eggs one at a time. Scrape the sides of your bowl and beat a little more to make sure everything is well combined.
Add in baking powder + salt + vanilla, beat to combine.
With the mixer on low speed add the flour and milk alternating half each at a time, work quickly here we do not want to over mix. Turn off the mixer.
In a small bowl mash 1/2 a cup of blueberries with your hand. Increase mixer speed to high and immediately add mashed blueberries mix for 10 seconds. Reduce speed to low and add the rest of the blueberries until fully incorporated. Let the mixture rest for one hour.
When there are about 20 minutes left of your rest period preheat the oven to 220°C. We use the setting with the fan. This ensures even distribution of heat.
Grease a muffin pan with nonstick spray or vegetable oil. Do not mix the batter. Using an ice cream scoop or large spoon fill the cavities of the muffin tin to the top.
Grab your premade streusel, squeeze some of the mixture in your hand, and then break apart above each muffin cavity.
Place muffins in preheated oven for 5 minutes. Then turn down the heat to 170°C cook for 18 -20 minutes.
Let them cool in the muffin pan for 5 minutes. Then remove them from the pan and let continue to cool on a wire rack.
