Preheat oven to 375º F and line a muffin tin with cupcake liners
In a large mixing bowl or stand mixer, combine the butter and sugar until fluffy, about 2 minutes
Add in the eggs, sour cream and vanilla. Continue to mix until well combined, another 2 minutes
Sift the flour, salt and baking powder into the butter mixture. Mix with the mixer until everything is combined, scraping down the sides to make sure everything gets mixed in.
Use a spatula to fold the blueberries into the muffin batter
Scoop the batter into the prepared muffin pan, filling them 3/4 of the way full
For the topping, combine the butter, flour, brown sugar, sugar and cinnamon until it is like sand. Sprinkle over the tops of the muffins before baking.
Bake the muffins for 25-30 minutes, until a toothpick comes out clean
Video
Notes
Nutrition facts are just an estimate
Frozen blueberries can be used in this recipe, just be sure to keep them frozen until adding to the batter so no extra moisture is added