In a medium sized bowl, whisk to combine the flour, baking soda, salt and cinnamon. Set aside.
In a large mixing bowl, add the sugars and lemon zest. Use your fingertips to rub the zest into the sugar. This helps to bring out the lemon flavor.
Add the butter. Using a handheld or stand mixer beat the medium speed, beat the butter, sugars and zest for 2 minutes.
Add the egg followed by the yolk and mix until just combined. Add the lemon juice and vanilla extract.
Using a spatula, fold in the dry ingredients until just combined. Do not overmix. Stir in optional white chocolate (if using). Very gently stir in the blueberries until combined.
Form the dough into 2 tablespoon sized balls. Place on a baking sheet and cover sheet tightly with plastic wrap. Chill in the fridge for 2 hours.
Preheat oven to 370 degrees when ready to bake. Place cookie dough balls 3 inches apart on a parchment paper lined baking sheet. Bake 9-11 minutes or until edges begin to turn golden brown.
Allow to cool slightly on the baking sheet then transfer to a rack to cool completely.
Notes
Lemons: *This recipe calls for 2 lemons. Use the zest of both lemons and 1 tablespoon of lemon juice. Blueberries: If you do not have fresh blueberries, you can make this lemon blueberry cookie recipe using wild frozen blueberries. Do not thaw them before adding to the dough. Stir them in right before scooping the dough. Storage: Store these lemon and blueberry cookies at room temperature in an airtight container for up to 4 days. Store leftover cookies in a freezer safe bags for up to 30 days. Thaw at room temperature or in the refrigerator.
Nutrition Information: The nutrition information provided is an estimate. The calorie accuracy is not guaranteed.