Preheat oven to 180°C/350°F. Grease an 8x8 baking dish with butter or oil.
In a medium bowl, stir together the oats, cocoa powder, baking powder and salt. Set aside.
2 cups rolled oats, ¼ cup cocoa powder, ½ teaspoon baking powder, ¼ teaspoon fine sea salt
In a large bowl, whisk together the peanut butter, egg and maple syrup until smooth. Next, gradually whisk in the milk until well combined.
½ cup smooth natural peanut butter, 1 large egg, 6 tablespoons pure maple syrup, 1 ¾ cups milk
Add the dry ingredients to the wet ingredients and stir to combine, making sure everything is well mixed. Stir in the chocolate chips.
½ cup chocolate chips
Pour the mixture into the prepared baking dish. Dollop some extra peanut butter on top and use a cocktail stick to swirl. Add extra chocolate chips too, if desired.
Bake for 35-40 minutes or until set. Cut into 6 squares and serve.