Preheat the oven to 350°F. Lightly grease an 8x8-inch baking pan with nonstick spray and line it with parchment paper, allowing the edges to hang over for easy removal.
Place the butter and chocolate chips in a microwave-safe bowl and heat in 15-second intervals, stirring thoroughly after each, until fully melted and smooth.
Incorporate the granulated and brown sugars into the melted mixture, stirring until well blended.
Crack in the eggs and beat thoroughly until the batter becomes cohesive and glossy.
Fold in the flour, stirring just until no streaks or lumps remain.
Transfer the batter into the prepared pan, smoothing the surface evenly.
Drizzle the caramel sauce over the top, then use a knife to gently swirl it through the batter to create a marbled effect.
Place in the oven and bake for 23 to 25 minutes, or until the edges are firm and the center appears just slightly underbaked.
Allow the brownies to cool completely in the pan before cutting into squares.