Step 1Place a rack in the center of the oven; heat the oven to 375 degrees. Line 8 muffin cups with paper liners or grease the cups.
Step 2Whisk together the zest, sugar, oil, buttermilk and lemon extract in a mixing bowl. Reserve 1 tablespoon of flour; add the rest to the bowl along with the baking soda and salt. Mix well. Toss the blueberries with the tablespoon of flour, then stir them into the batter. Fill the cups 3/4 full with batter.
Step 3Bake the muffins until well-browned, about 25 to 30 minutes. Gently brush the lemon juice mixture over each. Cool at least 30 minutes before serving.