Preheat oven to 180°C (350° F).
In a bowl, whisk eggs, melted coconut oil with peanut butter, packed brown sugar, vanilla extract and mix until incorporated.
Add oat flour, almond flour, baking powder and mix until well-combined.
Mix the cocoa powder with the milk. Divide the batter in two and add the cocoa and milk mixture to one half of it.
Pour both halves of the batter one at a time into greased pan (or lined with parchment paper), add chocolate chips and bake for 24 minutes.