01 - Preheat the oven to 350°F. Line two baking sheets with parchment paper.
02 - Combine ground flaxseed with water in a small bowl and let sit for 5 minutes to thicken.
03 - Whisk together flour, baking soda, baking powder, and sea salt in a large bowl.
04 - In a separate bowl, whisk brown sugar, melted coconut oil, plant milk, vanilla extract, and the prepared flax egg until smooth.
05 - Gradually add the wet ingredients to the dry ingredients, stirring until just combined without overmixing.
06 - Scoop tablespoon-sized portions of dough onto prepared baking sheets, spacing approximately 2 inches apart.
07 - Bake for 10 to 12 minutes until edges are set and tops are slightly crackled.
08 - Allow cookies to cool on the baking sheet for 5 minutes before transferring to a wire rack.
09 - Once fully cooled, dust cookies generously with powdered sugar.