Preheat oven to 350 degrees F. Grease or line an 9x13" baking pan, set aside. In a small mixing bowl combine the flour, baking powder, and salt, stir to combine and set aside.
In a large mixing bowl, combine the melted butter and peanut butter, mix until combined. Add in the sugars and mix for an additional 1-2 minutes. Add in the eggs, one at a time and the vanilla.
Slowly add in the dry ingredients and mix until combined. Fold in the chocolate and oats, transfer into the prepared baking pan. If desired, top with extra chocolate chips.
Bake at 350 degrees for 22-25 minutes or until a toothpick inserted comes out clean. Remove form the oven and let cool on a wire rack, sprinkle with flaky salt and allow to cool before cutting.