Preheat the oven to 350°F (175°C). Line a jumbo muffin tin with 6 jumbo muffin liners or grease the tin well.
In a large mixing bowl, combine the mashed bananas, granulated sugar, brown sugar, vegetable oil, egg, and vanilla extract. Mix until smooth and well combined.
In a separate bowl, whisk together the all-purpose flour, baking soda, baking powder, salt, and ground cinnamon.
Gradually add the dry ingredients to the wet ingredients, stirring gently until just combined. Do not overmix; the batter should be slightly lumpy.
Divide the batter evenly among the 6 jumbo muffin cups, filling each about 3/4 full.
Bake in the preheated oven for 22 to 25 minutes, or until a toothpick inserted into the center of a muffin comes out clean.
Remove the muffins from the oven and allow them to cool in the tin for 5 minutes.
Transfer the muffins to a wire rack to cool completely before serving.