01 - Preheat the oven to 350°F and line two baking sheets with parchment paper.
02 - Mix the ground flaxseed with water in a small bowl to make the flax egg; let sit for 5 minutes to thicken.
03 - Whisk together the flour, cocoa powder, baking soda, baking powder, salt, cinnamon, and nutmeg in a large mixing bowl.
04 - Whisk the brown sugar, granulated sugar, melted coconut oil, plant-based milk, vanilla extract, and prepared flax egg in a separate bowl until smooth.
05 - Add the wet ingredients to the dry ingredients and mix until just combined.
06 - Fold in the chocolate chips, dried fruit, and nuts if using.
07 - Scoop tablespoon-sized portions of dough onto the prepared baking sheets, spacing them about 2 inches apart.
08 - Bake for 10-12 minutes, until the edges are set but centers are still slightly soft.
09 - Cool on the baking sheet for 5 minutes, then transfer to a wire rack to cool completely.