Add the melted butter and granulated sugar to a large bowl and whisk to combine. 

Add the egg, vanilla extract, and lemon extract. Whisk to combine. 

Next add the flour, lemon zest, and baking soda. Fold the dry ingredients into the wet ingredients until no large lumps of flour remain. 

Add the blueberries and very carefully fold them into the cookie dough. 

Cover the cookie dough and place it in the fridge to chill for at least 30 minutes. 

When the cookie dough has chilled, preheat the oven to 350F and line a large baking sheet with parchment paper. 

Scoop out 2-tablespoon sized portions and place them on the parchment lined baking sheet. Make sure to place the cookie dough balls at least 2” apart. 

Bake the cookies for 10 minutes. Then remove them from the oven and tap the tray on the counter to sink the center of the cookies. Run a large round cookie cutter around the edge of each cookie to shape it into a circle (this will help the cookies finish baking and prevent the edges from browning). 

Return the cookies to the oven for another 3-5 minutes, or until they are golden brown. 

Allow the cookies to cool completely on the pan before transferring them to an airtight container.