Preheat your oven to 350°F (175°C). Lightly grease a 9-inch square baking dish or a similar-sized casserole dish with butter.

1. Prepare the bananas.Slice the bananas into thick rounds and place them in a large bowl. Add the granulated sugar, brown sugar, cinnamon, nutmeg, lemon juice, vanilla extract, and melted butter. Toss gently until the bananas are evenly coated.
2. Mix the dry ingredients.In a separate bowl, whisk together the flour, sugar, baking powder, salt, and cinnamon. This helps distribute the baking powder evenly for a light, tender topping.
3. Add the wet ingredients.Pour the milk, melted butter, and vanilla extract into the dry mixture. Stir until just combined. The batter should be smooth but slightly thick. Avoid overmixing to keep the topping tender.
4. Assemble the cobbler.Spread the banana mixture evenly across the bottom of the prepared baking dish. Spoon the cobbler batter over the bananas, spreading it gently. Leave a few small gaps so the fruit juices can bubble through as it bakes.
5. Bake until golden.Place the dish in the preheated oven and bake for 40–50 minutes, or until the topping is golden brown and the filling is bubbling around the edges. If the top browns too quickly, loosely cover it with foil for the remaining baking time.
6. Let it rest.Remove the cobbler from the oven and allow it to rest for 10–15 minutes. This gives the filling time to settle while keeping the dessert warm and spoonable.
7. Serve and enjoy.Spoon the warm banana cobbler into bowls. Add a scoop of vanilla ice cream, whipped cream, or a drizzle of caramel sauce for an extra-special Southern dessert.