Preheat your oven to 375°F (190°C). Line a 12-cup muffin tin with paper liners.
Mix dry ingredients: In a large bowl, whisk together flour, sugar, baking powder, baking soda, salt, and lemon zest.
Mix wet ingredients: In a separate bowl, whisk milk, oil, eggs, lemon juice, and vanilla until smooth.
Combine: Pour wet ingredients into the dry and stir gently until just combined (don’t overmix!).
Toss blueberries with 1 tbsp flour, then fold them into the batter.
Fill muffin cups about ¾ full. Sprinkle a little extra sugar on top if you like a crunchy lid.
Bake for 18–20 minutes, or until a toothpick comes out clean.
Cool in the pan for 5 minutes, then transfer to a rack. Enjoy warm or at room temperature!