01 -
Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper to prevent sticking.
02 -
In a medium bowl, whisk together the flour, baking powder, baking soda, and salt. Set aside.
03 -
In a large mixing bowl, beat the softened butter and granulated sugar until light and fluffy, about 3-4 minutes using an electric mixer.
04 -
Add the egg and vanilla extract to the butter mixture and mix until fully incorporated and smooth.
05 -
Gradually add the dry ingredients to the wet mixture, stirring until just combined. Be careful not to overmix, which can make the cookies tough.
06 -
Gently fold in the fresh blueberries and lemon zest. If using, add purple food coloring at this stage and mix until the dough is evenly colored.
07 -
Scoop the cookie dough into 1-inch balls and place on the prepared baking sheet. Flatten each ball slightly with your hand and sprinkle with coarse sugar.
08 -
Bake for 12-15 minutes, or until the edges are lightly golden. The centers may still look slightly underbaked, which is perfect for a soft, chewy texture.
09 -
Allow the cookies to cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.