Mix the dry ingredients: Preheat the oven to 375 degrees Fahrenheit. In a large mixing bowl, whisk together the all-purpose flour, baking powder, and salt.
Make the batter, wet ingredients: In a stand mixer, cream together the 1 cup granulated white sugar and 1/2 cup unsalted butter, until creamy and smooth.
Add the blueberries: In a small bowl, mash 1/2 cup of blueberries, and fold them into the batter. Fold in the remaining whole blueberries, reserving some for topping the muffin batter before baking.
Make the muffins: Line a 12-cup muffin tin with cupcake liners, add 1/4 cup muffin batter to each muffin cup and distribute any remaining batter evenly.