Preheat oven to 350 degrees.
In a large bowl, beat together the sugar, cocoa, oil, eggs and 1 1⁄4 cup milk. Combine the flour, salt and baking powder; gradually add to egg mixture until well blended. Fold in chocolate chips.
Spoon two thirds of the batter into a greased 13-in. x 9-in. baking pan. Bake for 12 minutes.
Meanwhile, in large saucepan, heat caramels, sweetened condensed milk and 1⁄2 cup milk over low heat until caramels are melted. Pour over baked brownie layer.
Drop remaining batter by spoonfuls over caramel layer; carefully swirl with knife.
Bake for 35-40 minutes or until a toothpick inserted in center comes out with moist crumbles (do not over bake). Cool on wire rack.