Preheat your oven to 300°F (150°C) and line an 8-inch square baking dish with parchment paper.

In a mixing bowl, combine gluten-free graham cracker crumbs, light brown sugar, and melted unsalted butter. Stir until it resembles wet sand. Press into the bottom of the prepared baking dish and refrigerate for 15 minutes.

Beat the room-temperature cream cheese in a large bowl until it's smooth, then gradually add sweetened condensed milk, sour cream, and vanilla extract until fully combined.

Gently fold in the mashed bananas into the creamy mixture, ensuring a smooth consistency with small banana chunks.

Pour the filling over the chilled crust and spread evenly. Bake for approximately 40 minutes, until edges are set and the center is slightly jiggly.

Cool at room temperature for about 30 minutes, then refrigerate for at least 4 hours before slicing.

Slice into squares and serve with optional toppings like chocolate syrup or whipped cream.