Preheat oven to 350°F (175°C). Grease or line a 9×5-inch loaf pan.
In a large bowl, mash bananas until mostly smooth.
Stir in sugars, melted butter, eggs, and vanilla until combined.
In a separate bowl, whisk flour, baking soda, and salt.
Gently fold dry ingredients into the banana mixture until just combined.
Pour half the batter into the prepared pan. Drizzle with half the salted caramel.
Add remaining batter and drizzle with remaining caramel. Swirl gently with a knife.
Bake for 50–55 minutes, until a toothpick inserted comes out with a few moist crumbs.
Cool in the pan for 10 minutes, then transfer to a wire rack to cool completely.