Preheat your oven to 350ºF (180ºC). If you haven't already, mix the ground flax seeds with the water in a small bowl. Let it sit for 5 minutes, or until it thickens and becomes gel-like.
1 tablespoon ground flax seed
To a large bowl, add the peanut butter and light brown sugar. Either using a whisk, an electric mixer, or a stand mixer, beat them together for 2-3 minutes, or until smooth.
1 cup natural creamy peanut butter, ⅔ cup packed light brown sugar
Add the wet ingredients - almond milk, flax egg, and vanilla extract, and mix until well combined.
3 tablespoons almond milk, 1 teaspoon vanilla extract
Then, add the dry ingredients - oat flour, baking soda, and salt. Fold them in using a silicone spatula until you have a smooth dough.
1 cup oat flour, ½ teaspoon baking soda, ¼ teaspoon salt
Add the chocolate chips and mix once again, until they're evenly distributed. Using a cookie scoop or a heaping tablespoon, scoop out some of the dough and roll it between your hand until you have a smooth ball.
⅔ cup dairy-free chocolate chips
Press it lightly to flatten it out and add it to a cookie sheet layered with parchment paper. Add a few more chocolate chips on top if desired. Make sure to leave enough space between each cookie so the edges can crisp up.
Bake on the middle rack for 10-12 minutes, or until the edges are golden brown, but the center is still soft. Let the oat flour cookies cool on the baking sheet for 10 minutes, then carefully transfer them to a wire rack, and let them cool completely.