Creating this Decadent Banana Upside Down Cake with Caramel is a breeze if you follow these simple steps:

1. Preheat the Oven: Preheat your oven to 350°F (175°C). Prepare a 9-inch round cake pan by greasing it with butter or cooking spray.
2. Make the Caramel: In a medium saucepan, melt the butter over medium heat. Stir in the granulated sugar and brown sugar until combined. Allow it to simmer for about 2-3 minutes, until bubbly. Remove from heat and stir in the vanilla extract.
3. Arrange the Bananas: Pour the caramel mixture into the bottom of the prepared cake pan. Arrange the sliced bananas on top of the caramel mixture in a decorative pattern.
4. Mix Dry Ingredients: In a large bowl, whisk together the flour, baking powder, baking soda, and salt.
5. Mix Wet Ingredients: In another bowl, beat the eggs and granulated sugar until light and fluffy. Stir in the buttermilk until well combined.
6. Combine Mixtures: Gradually add the dry ingredients to the wet ingredients, mixing until just combined. Be careful not to overmix.
7. Pour Batter: Carefully pour the cake batter over the bananas and caramel in the pan, spreading it evenly.
8. Bake: Place the cake in the preheated oven and bake for 30-35 minutes, or until a toothpick inserted into the center comes out clean.
9. Cool the Cake: Once baked, remove the cake from the oven and let it cool in the pan for about 15 minutes. Then, carefully invert it onto a serving plate so the bananas are on top.
10. Serve: Allow the cake to cool slightly before slicing and serving.

These steps will guide you in creating this decadent cake with ease.