Preheat the oven to 350°F. Spray a 9x13-inch pan generously with cooking spray.
PREPARE THE CARAMEL:
In a medium saucepan over low heat, combine the caramels and sweetened condensed milk. Stir often until the caramels are melted and the mixture is smooth. Remove from heat and let it sit while you prepare the brownies.
PREPARE THE BROWNIES:
Melt the butter in a pyrex cup in the microwave. Set aside and let cool. In a large bowl, whisk together the sugar and eggs. Add the cocoa powder and milk. Slowly whisk in the melted butter.
In a separate bowl, sift the flour, baking powder and salt. Whisk the dry ingredients into the chocolate mixture. Stir in the chocolate chips. Pour two thirds of the batter into the prepared pan. Place in the oven, and bake for 15 minutes.
Carefully remove the brownies from the oven and pour the cooled caramel over the top. The caramel will appear heavy compared to the brownie batter, and it will appear to sink to the bottom of the pan in some places- this is normal. Drop spoonfuls of the remaining batter over the caramel. Use a knife to gently swirl it into the caramel.
Return the pan to the oven and bake for 25 to 30 more minutes. The brownies should feel springy to the touch, and a toothpick inserted into the center shouldn't draw out raw batter. Remove from the oven and let cool on rack for about an hour. Cover with foil and place the pan in the refrigerator overnight- these must be chilled very well before you cut into them.
When you're ready to serve these, you'll need a sharp knife, a metal spatula and some cooking spray. Use the sharp knife to cut around edge of pan. Wipe the knife with a paper towel. Cut through brownies to make rows, wiping knife clean with a paper towel after eat cut. Spray a metal spatula with cooking spray and use it to scoop out the brownies. The brownies will be ooey gooey, so be sure to wipe the spatula with a paper towel after you remove each brownie.
The best way to serve these ooey gooey brownies is to place them on individual cupcake papers and just set the papers on a tray. Stick a plastic fork into the top of each one and they'll be ready to eat.