1. Preheat your oven to 425°F (218°C). Spray your muffin tin with cooking spray all over (not just in the cups) because this will help prevent the dome part of the muffins from sticking to the pan. Line the muffin pan with paper liners.
2. In a large mixing bowl, combine the flour, baking powder, baking soda, and salt. Set aside.
3. In another mixing bowl, whisk together the melted butter, granulated sugar, eggs, milk, lemon zest, lemon juice, and lemon extract until well combined.
4. Pour the wet ingredients into the dry ingredients and mix gently with a spatula until just combined. Be careful not to overmix, as this may result in dense muffins.
5. Carefully fold in the blueberries, ensuring even distribution throughout the batter.
6. Fill the muffin cups to the rim full with batter. Filling the muffin tin to the rim will help you create that beautiful muffin top dome! Just be sure to spray the tin with cooking spray all over the pan, not just in the muffin cup part!
7.  Bake muffins in the preheated oven for 5 minutes at 425°F (218°C), then reduce the oven temperature to 375°F (190°C) and continue to bake for an additional 13-15 minutes or until a toothpick inserted in the center comes out clean (or with a few moist crumbs attached). This two-step baking process allows the muffins to rise efficiently and form a nice dome shape.
8. Remove the muffins from the oven.
9. After the muffins have finished baking and are still warm, use a toothpick or skewer to poke several holes in the tops of each muffin.
10. Carefully spoon or brush the Lemon Simple Syrup over the tops of the warm muffins, allowing it to soak into the holes and infuse the muffins with an extra burst of lemon flavor.
11. Let the muffins cool in the pan for a few minutes before transferring them to a wire rack to cool completely.

Lemon Simple Syrup Instructions:

1. While the muffins are baking, prepare the Lemon Simple Syrup by combining the sugar, water, and lemon zest in a small saucepan over medium heat.
2. Stir occasionally until the sugar dissolves, allowing the mixture to come to a gentle simmer.
3. Once the sugar has dissolved, remove the saucepan from the heat, and stir in the fresh lemon juice.
4. Allow the Lemon Simple Syrup to cool slightly while the muffins finish baking.