Preheat your oven to 350°F (175°C). Grease a 9x13-inch baking pan or line it with parchment paper for easy removal.
In a large mixing bowl, combine the melted butter and granulated sugar. Stir until well blended.
Add the eggs one at a time, mixing well after each addition. Stir in the vanilla extract.
In a separate bowl, whisk together the flour, cocoa powder, and salt. Gradually add the dry ingredients to the wet mixture, stirring until just combined.
Gently fold in the cornflakes and chocolate chips (if using) until evenly distributed.
Pour the brownie batter into the prepared baking pan and spread it evenly.
Drizzle the caramel sauce over the top of the brownie batter, using a knife or spatula to swirl it into the mixture slightly.
Bake in the preheated oven for 25-30 minutes, or until a toothpick inserted into the center comes out with a few moist crumbs.
Allow the brownies to cool in the pan for at least 15 minutes before cutting into squares and serving.