Preheat your oven to 350°F. Line a 13x9-inch baking pan with foil and lightly spray it with cooking spray. In a medium saucepan, melt the butter over low heat. Stir in the chocolate chips and continue melting, stirring frequently until smooth and free of lumps. Remove from heat, then stir in the sugar and vanilla extract. Add the eggs one at a time, mixing well after each addition until the batter is smooth and glossy. Gently fold in the cocoa powder, salt, and flour until just combined. Pour half of the brownie batter into the prepared pan and bake for 20 minutes. While the brownies bake, prepare the caramel filling by combining the caramel bits and whipping cream in a small saucepan. Heat over low heat, stirring frequently, until smooth and melted. After 20 minutes, take the brownies out of the oven and evenly spread the caramel mixture over the top. Sprinkle one cup of the remaining chocolate chips over the caramel layer. Pour the remaining brownie batter on top, spreading it evenly to cover the caramel and chocolate chips. Return the pan to the oven and bake for an additional 30 minutes. Allow the brownies to cool completely before lifting them out of the pan and slicing.