Mix the ground flaxseed and water in a small bowl and set aside to gelatinize into a flax egg.

In the bowl of your stand mixer with the paddle attachment or a large bowl using a handheld mixer, beat the softened butter, brown sugar, and granulated sugar until creamy, about 1-2 minutes. Add in the flax egg and vanilla, scraping down the sides of the bowl as needed.

Add the flour, oats, baking soda, cinnamon, and salt. Mix on low-medium speed until just combined, then fold in the dairy free chocolate chips.

Cover the bowl and refrigerate for 30 minutes. Once refrigerated, preheat the oven to 350F and line two baking sheets with parchment paper.

Using a 1 tablespoon cookie scoop, roll the cookie dough into balls and place each on the baking sheets.

Bake for 12 minutes, or until the cookies are lightly golden around the edges are set. It's okay if the centers look a little underdone, the cookies will firm up while cooling. For crunchy cookies, cook for an extra 1-2 minutes.

Once cooked, remove from the oven and let cool for 5 minutes on the baking sheets before transferring them to a wire rack.

Store oatmeal cookies in a sealed container at room temperature for 3-5 days or in the freezer for up to 2 months. Thaw for 30 minutes at room temperature before enjoying.