If you want to make homemade caramel for the top of the cake, I suggest making it first and placing it in the refrigerator to thicken a bit before using.
Preheat the oven to 350°F. Line a 8X8 metal baking pan with parchment paper.
Whisk together the flour, salt, baking soda, and spices, set aside.
Mash the bananas with the mixer on low until completely smooth, set aside.
Add the vegetable oil, vanilla extract, granulated sugar, brown sugar, sour cream, and eggs to the mashed bananas. Mix until well combined.
Gradually add the dry ingredients to the wet mixture, whisking gently until just combined. Be careful not to over mix.
Pour the batter into the prepared metal baking pan, smoothing the top with a spatula.
Position it on the center rack of the oven to ensure even baking, avoiding placement too close to the top or bottom. Bake in the preheated oven for 30-35 minutes, or until a toothpick inserted into the center comes out clean.
Let the cake cool before frosting. I like to trim the domed top of the cake to make it level, and bonus, the scraps are a little treat for you!