Preheat oven to 350°. Spray or butter an 8×8 baking pan; line pan with parchment paper, pressing against sides (leave overhang intact for easy removal of brownies). Butter or spray parchment paper. Whisk sugars and vanilla with melted butter until smooth. Add eggs, one at a time, whisking until pale and combined well. Combine flour, cocoa powder and salt. Add dry ingredients all at once to wet, scraping down sides of bowl and stirring gently with spoon or spatula until no dry spots remain (do not overmix). Stir in chocolate chips and chunks, reserving ¼ cup for topping.
Spoon half of brownie mixture into prepared pan, roughly spreading in a thin layer across entire pan. Drizzle caramel sauce over brownie mixture in pan, however, do not spread (allow for some pooling and pockets of caramel to develop when baking). Spoon remaining brownie mix over top of caramel, gently spreading (brownies will look rough, with some caramel exposed; this is normal and allows for random gooey pockets of caramel). Sprinkle with Himalayan pink salt or flake salt and scatter remaining chocolate chips over top.
Bake 30 min until center is set (will be wet, but will not wiggle when pan is bumped lightly). Let cool completely before cutting. When cool, lift brownies from pan using parchment overhang. Peel paper away and cut into squares. Serve at room temp. Store any extras chilled in airtight container.