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 the mixture resembles wet sand.

Press the mixture into the bottom of the prepared baking dish and refrigerate.

In a separate bowl, beat the room-temperature cream cheese until smooth. Gradually add sweetened condensed milk, sour cream, and vanilla extract, mixing until smooth.

Gently fold in the mashed ripe bananas using a spatula, careful not to overmix.

Pour the banana cheesecake filling over the crust and bake for about 40 minutes until the filling is firm.

Cool completely at room temperature for about 1 hour, then refrigerate for at least 4 hours.