Beat eggs with both sugars and salt on medium speed until light and pale in color, about 3-4 minutes.
Sift in cocoa powder and flour. Blend on low until incorporated.
Slowly add butter until well combined. Blend in vanilla.
Stir in chocolate chips and spread half of batter into the prepared pan. Set aside.
Make Caramel Layer
In a small saucepan over medium low heat, melt caramel bits with sweetened condensed milk, stirring often, until smooth.
Pour caramel mixture over brownie batter in pan.
Finishing Layering and Baking
Dollop the second half of the brownie batter evenly over the caramel and gently spread it as far to the edges as possible (it's okay if it doesn't cover the caramel layer completely.
Bake for 45-55 minutes, or until a toothpick inserted into center comes out with only a few wet crumbs attached.
Let cool completely. Remove brownies from pan and cut into 2-inch pieces. For perfect cuts, refrigerate brownies until completely cold to get nice even squares.
Brownies can be stored covered at room temperature or refrigerated for 4 days. Leftovers may be frozen. Thaw before serving.
Notes
If you can't find caramel bits where you live, use the same amount in weight of square caramels that have been unwrapped.