Preheat your oven to 350°F (175°C) and line a muffin tin with cupcake liners.
In a mixing bowl, whisk together the flour, sugar, baking powder, and salt.
Add the softened butter and mix until the mixture resembles coarse crumbs.
Beat in the eggs one at a time, then stir in the vanilla extract.
Gradually add the milk, mixing until just combined. Fold in the blueberries.
Divide the batter evenly among the cupcake liners, filling each about ⅔ full.
Bake for 18-20 minutes, or until a toothpick inserted into the center comes out clean.
Allow the cupcakes to cool in the tin for 5 minutes, then transfer to a wire rack to cool completely.