Begin by preparing your oat flour for the Brownie Bowl for Two. Place rolled oats into a blender or food processor and blend until they resemble a fine flour texture, about 30 seconds.

In a medium mixing bowl, combine the freshly made oat flour, unsweetened cocoa powder, and baking powder. Mash one ripe banana and add it to the dry ingredients, along with vanilla extract and any optional add-ins like walnuts. Stir until thoroughly combined.

Carefully transfer the brownie mixture into a small oven-safe dish or ramekin, spreading it evenly across the bottom.

Preheat your oven to 350°F (about 175°C) and place the filled ramekin inside. Bake for 10-12 minutes, watching closely until the edges are set but the center remains soft and gooey.

Once the brownie has baked to perfection, carefully remove it from the oven and let it cool for a minute. Serve warm directly in the ramekin, topped with your choice of vanilla ice cream, peanut butter, or other toppings.