Preheat oven to 425°F (218°C). Line a 12-cup muffin tin with paper liners.
In a large bowl, rub the lemon zest into the sugar with your fingers until fragrant.
Whisk the flour, baking powder, baking soda, and salt into the lemon sugar.
In a separate bowl, whisk the melted butter, oil, eggs, buttermilk, 3 tablespoons lemon juice, and vanilla.
Gently fold the wet ingredients into the dry ingredients until just combined. Do not overmix.
Toss the blueberries with 1 teaspoon of flour, then gently fold them into the batter.
Let the batter rest for 15 minutes at room temperature.
Divide batter evenly among the cups. Bake at 425°F for 5 minutes, then reduce oven temperature to 350°F (175°C) and bake for another 15-18 minutes.