Step 1

Preheat the oven to 350 degrees F.

Step 2

Lightly grease an 8x10-inch baking dish.

Step 3

In a large bowl, mix the oats, the brown sugar, the flax seeds, the flour, the baking powder, the cinnamon, and the salt together.

Step 4

In another bowl, mix the banana, the rice milk, the egg, and the vanilla extract together.

Step 5

Pour the banana mixture into the flour mixture and stir to combine.

Step 6

Pour the batter into the prepared baking dish.

Step 7

Bake until a toothpick inserted into the center comes out clean, about 20 minutes.

Step 8

Cover the pan with a towel and allow the brownies to cool, about 5 minutes.

Step 9

Slice and serve.