Step 1

Heat oven to 350°F (180°C) and fold a 7 x 7 inch (15 x15 cm) brownie pan with parchment paper.

Step 2

In a large bowl mash the bananas and combine with yogurt, vanilla extract, cinnamon and a pinch of salt. For sweetener bars, add 2 to 4 tablespoons of maple syrup or honey to taste. Stir until smooth.

Step 3

Add rolled oats and protein powder to the wet mixture, then stir until combined. You can optionally add extra mix-ins, such as chocolate chips, walnuts or raisins.

Step 4

Transfer the dough to the prepared baking pan and spread it out evenly.

Step 5

Bake in hot oven for 15 to 20 minutes, or until they have set in the center. Let cool to temperature, then slice into bars.