Prepare the pan: line a 8-inch (20cm) square baking pan with parchment paper and set aside.
Make the peanut butter layer: Place the oats in a blender and blend into flour (you also can use store bought oat flour).
Transfer oatmeal flour into a bowl, add ground almonds, peanut butter, maple syrup, salt and mix until well combined.
Transfer the batter into prepared pan and spread evenly. Refrigerate while making the chocolate topping.
Make the chocolate topping layer: chop dark chocolate, place in a heatproof bowl, add coconut oil and melt in 15-20 second pulses in the microwave until completely melted.
Pour over the peanut butter layer and refrigerate for at least 30 minutes before serving.