Preheat your oven to 350°F. If you don't have oat flour, simply blend rolled oats in a blender until finely ground.
In a large bowl, mix together the rolled oats, oat flour, baking powder, salt, and ground flax.
In a separate bowl, combine the tahini, maple syrup, and vanilla extract, whisking until well combined.
Pour the dry ingredients into the bowl of wet ingredients and mix with a spatula until fully combined. Fold in the chopped dates and chocolate chunks.
Using a cookie scoop, form the dough into balls and place them on a parchment-lined baking sheet. Flatten each ball slightly with the palm of your hand.
Bake the cookies for 12 minutes, then allow them to cool for 5 minutes before transferring to a cooling rack or plate.