Preheat the oven to 180°C (350°F). Line a large baking tray with parchment paper and set aside.
In a large mixing bowl, combine the oat flour and protein powder and stir to blend evenly.
In a microwave-safe bowl, combine the peanut butter and maple syrup. Microwave briefly until the peanut butter softens and can be whisked smooth with the maple syrup.
Pour the wet mixture into the dry ingredients and mix until a thick, workable dough forms.
If making chocolate cereal, divide the dough in two and stir about 1/4 cup cocoa powder into one portion until fully combined.
Roll small balls of dough with your hands and place them on the prepared baking tray, leaving a little space between pieces.
Bake for 10–12 minutes, until the edges begin to firm. Remove from the oven and allow the cereal to cool completely on the tray.
