Preheat the oven to 350 degrees Fahrenheit. Line a large baking sheet with parchment paper.
Place your ground flaxseed and warm water in a small bowl or cup. Set aside. In a glass measuring cup or microwave safe bowl, melt your coconut oil. Set aside.
In a medium bowl, combine coconut sugar, organic cane sugar, almond flour, baking powder, baking soda, and salt. Whisk to combine. Add the peanut butter, vanilla extract, flax egg, and coconut oil. Stir until mixture is completely incorporated. Use your hands to mix and fully combine.
Chill cookie dough in the refrigerator for 30 minutes.
After 30 minutes, use a tablespoon to scoop out dough and roll into balls. You may need to squeeze the ball together and then roll it.
Place cookie dough balls in even rows on cookie sheet, with about an 1 ½ inches between each. Using a fork, make cross-hatch marks. Sprinkle with sea salt.
Bake for 13-15 minutes. Allow cookies to cool for a few minutes on the cookie sheet before transferring with a metal spatula to a wire rack.
Store in an airtight container for 2-3 days at room temperature or 4-5 days in the refrigerator.