Preheat oven to 350 °. Line cupcake tins with paper liners.

Sift 3 1/4 cup four, sugar, baking powder, baking soda, and salt in a large bowl. In another bowl mix the buttermilk, butter, lemon zest, and eggs until well mixed.

In a third bowl add the blueberries and sprinkle them with the reserved flour. Mix very gently not to break the blueberries. This will keep the blueberries from falling to the bottom of the muffins.

Add the wet ingredients to the dry and stir until just incorporated. Gently stir in the blueberries.

Distribute the batter evenly between 20 muffin cups. I like to use a standard size ice cream scoop to put muffin mixtures into the cups.

Bake for 20-25 minutes until they are golden brown and cooked through.