In a 12-inch nonstick skillet, melt the butter over medium-high heat until it begins to bubble. Add the bananas in a single layer and cook for 1 to 2 minutes, or until beginning to brown. Flip the bananas with a rubber spatula and brown them slightly on the reverse side. Sprinkle with the cinnamon and cook for another 30 seconds, stirring occasionally. Gently mix in the dulce de leche; simmer for 1 minute, then set aside to cool a bit. Serve over ice cream, with mini chocolate chips sprinkled over the top.