Preparation / Directions:
Mix the lime or lemon zest, coconut, almond flour, potato starch and sugar together to incorporate well; add 2 eggs, 3 egg whites, peanut oil or melted butter and the vanilla using a whisk or wooden spoon. Chill overnight or for up to 2 days. Preheat the oven to 375 degrees. Line baking sheets with baking parchment paper.
Place spoonfuls of batter on the prepared baking sheet, leaving plenty of room between each mound (8 to 10 per sheet). Dip the bottom of a 2-to 3-inch diameter glass in cold water, then flatten each mound into a circle of batter (continue dipping the glass for each cookie). Bake until golden brown on the edges and pale in the center, about 10 minutes. Cool on the sheet for about 10 minutes and then peel the paper off. Store in sealed containers, such as a cookie tin.