Heat oven to 375 degrees and line 12 standard muffin cups with paper or foil cupcake liners.
In a medium bowl, whisk together flour, salt, baking powder and baking soda, and reserve.
In a small bowl, using a fork, mash 1/2 cup blueberries, and reserve.
In a bowl of an electric mixer, combine sugar and lemon zest. Using your fingers, rub zest and sugar together until sugar is fragrant and moist. Add butter and, on medium-high speed, beat until light and fluffy, about 2 minutes.
Add the eggs, one at a time, beating well after each addition. Add vanilla extract and sour cream and beat until thoroughly incorporated. Reduce speed to low and add flour mixture, mixing until just incorporated; do not overmix. Batter will be thick and slightly lumpy.
Using a spatula, fold mashed blueberries into batter, then fold remaining berries into batter.