Prepare your flax egg by whisking together the ground flaxseed and water, and let it sit for 10 minutes.

In a large mixing bowl, combine melted coconut oil and granulated cane sugar, whisking until it resembles wet sand. Add the flax egg, vanilla extract, lemon juice, and lemon zest.

Sift flour, baking powder, and sea salt into the wet mixture and fold together until no dry streaks remain.

Chill the dough in the refrigerator for at least 1 hour.

Preheat the oven to 350°F (175°C) and line your baking sheets.

Scoop about one tablespoon of dough, roll it into a ball, then coat it in powdered sugar.

Place the balls on the baking sheet with space between them and bake for 10 to 12 minutes.

Allow cookies to cool on the baking sheet for 5 minutes before transferring to a wire rack.