Step 1

Preheat the oven to 350°F (180°C) and line a 7 x 7 inch (15 x 15 cm) brownie pan with parchment paper.

Step 2

In a large bowl, mash the ripe bananas. Add the peanut butter, vanilla extract (if using), and a pinch of salt. For sweeter bars, stir in 2 to 4 tablespoons of maple syrup or honey. Mix until smooth.

Step 3

Add the rolled oats and, if using, the protein powder. Stir until fully combined. If the mixture feels too dry, add a splash of milk or a bit more peanut butter.

Step 4

Spread the dough evenly into the prepared pan.

Step 5

Bake for 17 to 20 minutes, or until the center is set. Let cool completely before slicing into bars.