Preheat oven to 350ºF. Grease and flour a 9x9-inch baking pan. Set aside.
Melt butter and chocolate chips in a small saucepan over low heat. Remove from heat and cool.
In a bowl, mix together the vanilla, sugar and mashed bananas. Add the eggs and beat well. Mix until everything is well combined.
Sift flour and salt and add to banana mixture. Stir in salted caramel chips.
Fold in ⅔ of the chocolate mixture into the batter. Stirring until just combined. (it can make streaks in the batter)
Spread batter into prepared pan. Drizzle the remaining chocolate mixture on top of the batter. Use a knife to create streaks of chocolate.
Bake for 35 minutes, until a toothpick comes out clean.
Cool on a wire rack 1 hour before cutting. Store leftovers in refrigerator.
Notes:
I used Hershey's Salted Caramel Baking Chips.If you can't find Hershey's, Ghirardelli makes caramel baking chips. They will both be near the chocolate chips.