Preheat the oven to 350°F (175°C).

Prepare a 9x13-inch baking pan by greasing it lightly.

In a large mixing bowl, combine the chocolate cake mix, eggs, water, melted butter, and vanilla extract until well blended.

Pour half of the cake batter into the prepared pan, spreading it evenly.

Drizzle the caramel sauce over the batter, then sprinkle the chocolate chips on top.

Pour the remaining batter over the caramel and chocolate layers, smoothing the top gently.

Bake in the preheated oven for 30-35 minutes, or until a toothpick inserted comes out clean.

Remove from the oven and let it cool for about 10 minutes before serving.

Serve warm with whipped cream or vanilla ice cream, if desired.