Cream butter and granulated sugar until light and fluffy.
Add lemon juice, lemon zest, brown sugar, vanilla extract and egg and mix to combine.
Add approximately half of your gluten free baking flower to your mixture and mix well. Add remaining ingredients and mix until well combined.
Place ¼ cup of granulated sugar in a small dish. Working one tablespoon-sized scoop at a time, form round dough balls and press into flat discs. Coat all sides with granulated sugar and place on the prepared cookie sheet.
Bake 10-12 minutes or until the bottoms of the cookies are slightly brown. Leave on the cookie sheet for 5 minutes and then transfer to a wire cookie rack to cool completely.