Preheat your oven to 350°F (175°C). Grease a small cast iron skillet (6-8 inches) or baking dish.
In a medium bowl, whisk together peanut butter, maple syrup, egg (or flax egg), and vanilla extract until smooth.
Mix in the baking soda, salt, and oat flour until a thick dough forms and fold in the chocolate chips; NOTE: if using almond flour, you’ll need 1-2 tbsp of extra flour!
Press the dough evenly into your prepared skillet or baking dish and Sprinkle extra chocolate chips on top if desired.
Bake for 15-18 minutes until the edges are golden brown and the center is just set (it will continue cooking as it cools)
Let it cool for 5-10 minutes, then sprinkle with flaky sea salt if desired
Serve warm straight out of the skillet with a spoon or alongside vanilla Greek yogurt or your favorite ice cream
Enjoy!!!