Follow these easy steps to create your delicious blueberry muffins:

1. Preheat Oven: Preheat your oven to 375°F (190°C). Line a muffin tin with paper liners or grease it with cooking spray.

2. Mix Dry Ingredients: In a large bowl, whisk together the flour, sugar, baking powder, and salt until well combined.

3. Combine Wet Ingredients: In another bowl, mix the melted butter, yogurt, eggs, and vanilla extract until smooth.

4. Combine Mixtures: Pour the wet ingredients into the dry ingredients. Stir gently until just combined; be careful not to overmix.

5. Add Blueberries: Fold in the fresh blueberries and lemon zest if using, ensuring they are evenly distributed throughout the batter.

6. Fill Muffin Tin: Spoon the batter into the prepared muffin tin, filling each cup about ¾ full.

7. Bake: Place the muffin tin in the preheated oven and bake for 20-25 minutes, or until a toothpick inserted into the center comes out clean.

8. Cool: Remove the muffins from the oven and allow them to cool in the pan for about 10 minutes before transferring them to a wire rack to cool completely.

9. Enjoy: Once cooled, enjoy your blueberry muffins warm or at room temperature.

These straightforward steps make it easy for anyone to bake delicious blueberry muffins in no time!