Preheat your oven to 350°F (180°C) and grease an 8x8 inch baking pan with butter or cooking spray.
In a medium bowl, mash the ripe bananas with a fork until smooth.
In a large mixing bowl, cream together the butter and sugar until light and fluffy.
Add the eggs one at a time, mixing well after each addition.
Stir in the vanilla extract and mashed bananas until well combined.
In a separate bowl, whisk together the gluten-free flour blend, baking powder, baking soda, and salt.
Gradually add the dry ingredients to the wet ingredients, mixing well after each addition.
Pour the batter into the prepared baking pan and smooth the top with a spatula.
If desired, sprinkle chocolate chips, nuts, or dried fruit on top of the batter.
Bake for 25-30 minutes or until a toothpick inserted into the center comes out clean.
Let the cake cool for 10-15 minutes before slicing and serving.
Enjoy your delicious and healthy gluten-free banana snack cake!