These bright lemony cookies are are the perfect summer treat! Two of the best things collide, tart lemonade and sweet sugar cookies to create a fun, flavorful cookie everyone will love!
Preheat oven to 400 degrees. In a mixing bowl whisk together flour, baking soda, cream of tartar and salt for 20 seconds, set aside.
In the bowl of an electric stand mixer fitted with the paddle attachment blend sugar and lemon zest for 30 seconds until sugar appears slightly yellow and is fragrant.
Add butter and mix until combined. Mix in egg, then mix in egg yolk and vanilla extract.
With mixer set on low speed slowly add in dry ingredients and mix just until combined.
Scoop dough out 1 1/2 Tbsp at a time and shape into balls (note that if dough is too sticky for you to work with you can chill for about 30 minutes if needed).
Transfer to a baking sheet lined with parchment paper or a silicone liner, spacing cookies 2-inches apart.
Bake one sheet at a time in preheated oven 10 - 12 minutes (cookies should appear slightly under-baked).
Remove from oven and allow to rest several minutes then transfer to a wire rack to cool completely. Repeat until all of the dough has been used up.
Once cookies are cool frost cookies with lemon frosting.
For the frosting: In the bowl of an electric stand mixer blend butter until smooth.
Add in powdered sugar and lemon juice. Mix until slightly fluffy, while adding in cream to thin as needed.