Preheat the oven to 375 degrees. Line one 12 cup muffin tin with paper liners, or grease generously with butter, and set aside,
Whisk together the flour, salt and baking powder in a medium measuring cup. Set aside.
Combine the butter and 3/4 cup sugar in a mixing bowl. Whisk until fully combined and fluffy.
Add the eggs, one at a time, mixing well between each addition to incorporate.
Stir in the vanilla and lemon zest.
Mix in the dry ingredients and buttermilk until the dough forms.
Fold in the blueberries until just combined into the dough.
Divide the batter evenly between the muffin cups.
Sprinkle the tops of the muffins with the remaining 1 tablespoon of sugar.
Bake 20 to 25 minutes, or until a toothpick comes out clean and the tops are lightly browned.