Preheat the oven to 350°F.

Spray a 9x5-inch loaf pan with nonstick cooking spray. Set aside.

Place the mashed bananas, canola oil, granulated sugar, brown sugar, eggs and vanilla extract in a large mixing bowl. Whisk vigorously until smooth and combined.

Add the brown rice flour, oat flour, cornstarch, cinnamon, baking powder, baking soda, and salt to the bowl. Continue whisking until the mixture is just combined. Do not over-mix.

Pour the batter into the prepared loaf pan.

Bake the bread on middle rack of oven until a toothpick inserted in the center comes out clean, 45-60 minutes.

Check to see that bread is done. Remove from oven or add time as needed.

Allow the bread to rest in the pan for 10 minutes, then release the bread from the pan onto a cooling rack. Allow to cool for at least 1 hour before slicing and serving. Leftover bread may be stored in a large zip-top bag at room temperature for 1 day, in the refrigerator for 4 days, or in the freezer for up to 3 months.