Preheat the oven to 350°F (175°C) and grease an 8x8-inch baking dish.
In a large bowl, whisk together the rolled oats, cocoa powder, baking powder, and salt.
In a separate medium bowl, whisk together the milk, egg, maple syrup, vanilla extract, and melted coconut oil.
Pour the wet ingredients into the dry ingredients and stir until well combined.
Fold in 1/4 cup of the chocolate chips.
Pour the mixture into the prepared baking dish and spread evenly.
Sprinkle the remaining 1/4 cup of chocolate chips over the top.
Bake for 30 to 35 minutes, or until the center is set and the edges are slightly firm.
Remove from the oven and let cool for 5 to 10 minutes before serving.