Beat the butter and sugar in a large mixing bowl with an electric mixer for a few minutes until creamy.
Beat in the egg, then beat in the lemon juice, zest and vanilla.
Whisk the flour, baking soda, and salt in a small bowl to combine, then add to the wet ingredients and mix gently to combine.
Refrigerate for 30 minutes (in the bowl or wrap in plastic wrap).
Preheat the oven to 350F (175C). Line baking sheets with baking parchment paper.
Roll heaped teaspoons of dough into balls, place onto the cookie sheet (about 1 inch apart) and press down slightly with the back of a spoon.
Bake for 8-10 minutes or until the cookies are set and just beginning to brown around the edges.
Transfer the lemon cookies to a wire rack to cool.
Mix the powdered sugar and lemon juice to create a thick drizzling consistency. If using, add a drop or so of yellow food coloring.
Drizzle over the completely cooled cookies.
Notes
To make sure your batter is smooth and even, make sure all of your ingredients are at room temperature.The butter and sugar can be creamed together using a stand mixer with a paddle attachment, or by using a hand mixer on medium speed.Don't overwork the lemon cookie dough when mixing wet and dry ingredients as this could change the texture of the cookies.When adding the lemon glaze, be sure that the cookies are cooled completely or the glaze will melt. The lemon glaze will harden as it sits and dries out.