In a medium sized bowl, mix together flour, baking soda, and salt. Set aside.
In a large mixing bowl, mix together sugar and lemon zest using a fork until combined. Add the softened butter. Using an eclectic mixer, beat on medium-high speed for about 2-3 minutes or until light and fluffy.
Beat in the egg, egg yolk, lemon juice, vanilla extract, and yellow food coloring until combined and smooth. Don’t forget to scrape the bottom and the sides of the bowl to make sure all ingredients are well combined.
Add the dry ingredients to the wet mixture. Beat on low speed just until combined and no big lumps of flour remain. Don’t overmix. The dough should be thick. Cover the bowl with plastic wrap and place in the refrigerator for at least 4 hours or overnight.
Preheat the oven to 350°F. Line two baking sheets with parchment paper. Set aside.
Scoop the chilled dough and roll into 1 ½ inch balls. Then, roll evenly into granulated sugar and confectioner’s sugar. Place on the prepared baking sheet, leaving about 2 inches between each cookie.
Bake in the preheated oven for about 12-14 minutes or until the edges are set and the top cracked and puffed. The cookies should still be soft in the center.
Remove from the oven and let cool for about 5-10 minutes. Then, transfer to a cooling rack. Enjoy!