Preheat the oven to 175°C (350°F).
Blend the oats into a fine flour.
Mix all the dry ingredients.
In a separate bowl, whisk together the eggs, mashed banana, melted butter, Greek yogurt, maple syrup and vanilla.
Add the dry ingredients to the wet ingredients and mix until just combined.
Divide the batter evenly between two 12 cm (5-inch) cake pans lined with parchment paper.
Bake for 25–35 minutes, or until a toothpick inserted into the center comes out clean.
Let the cakes cool completely before decorating.
