• Beat sugar and butter with a hand held electric beater for 1 to 2 minutes (until creamy and fluffy).
• Add almond flour, lemon juice, lemon zest and salt, continue beating for about 30 seconds or until thoroughly combined.
• Remove beater and stir cookie dough with a rubber spatula to shape into one mass. Using hands, shape dough into a ball (if dough feels sticky, then mix in an additional tablespoon or two almond flour) and flatten slightly.
• Place dough ball between two sheets of parchment paper and roll to about ¼-inch thickness.
• Transfer cookie dough (along with parchment) onto a baking sheet and refrigerate overnight (or up to 2 days).
• When ready to bake, pre heat oven to 325° F and line a baking sheet with parchment paper. Cut cookies into circles using a 3-inch cookie cutter and cut each circle in half, using a sharp knife.

  Gently transfer cookies to the baking sheet (spacing about an inch apart). Re roll remaining dough to make more cookies.
• Bake for 16 to 18 minutes or until the edges get deep golden in color. Place baking sheet on a wire rack and cool completely.

Icing

• Make white icing

  Add 1 and ½ cups confections sugar and 2 to 3 teaspoons lemon juice into a small bowl and mix to get a "piping consistency" (When lifted from the surface with a spoon, it forms a soft peak and doesn't flow back into the rest of the icing. Not too thick that it’s hard to stir nor too thin that it settles into a flat surface after several seconds). Transfer to a piping bag or a quart size zip lock bag and close to seal.

  Make yellow icing

  Add 1 and ½ cups confections sugar, lemon zest, 2 to 3 teaspoons lemon juice and a dash of lemon food color into a another small bowl and mix until "flooding" consistency (Icing needs to be a little runny, but still thick enough to hold its shape, like honey)
• Adjust food color as needed. Transfer to a piping bag or a quart size zip lock bag and close to seal.

Decorate

• Begin by using the yellow icing

   – Snip off the end tip of the piping bag. Spread yellow icing all over the top of the cookies, leaving a ⅛-inch border. Arrange the cookies on a baking sheet to dry for about 5 to 10 minutes.
• Finish by using white icing 

  – Cut a small tip from the end of the piping bag. Begin from the cookie you iced first (which will be almost set by this time), pipe a border around the edge of the cookie (bordering the yellow icing). Now, pipe three line from the middle of the straight line towards the semi circle to resemble a lemon slice.
• Let cookies set for a few hours.