Make sure the oven rack is in the middle of the oven and preheat oven to 350.
Prepare a 9 x 13″ baking pan with heavy duty aluminum foil and then lightly grease the foil lined pan.
Cut the butter into 1″ pieces and place in a heavy saucepan.
Be sure to melt the butter on the lowest setting.
While the butter is melting, chop the unsweetened chocolate and add it to the melted butter along with the 60% chocolate chips.
Whisk until melted and smooth, then turn off the heat and leave the saucepan on the burner while you continue with the rest of the recipe.
In a large bowl lightly whisk the eggs.
Place the sugars and salt in a small bowl and then add to the eggs until just incorporated.
Briefly whisk the chocolate and then gradually whisk it into the egg mixture until just combined.
Briefly whisk in the vanilla.
Place the flour and the baking powder in the small mixing bowl, whisk to combine.
Sift through a strainer directly over the chocolate batter.
Stir in with a spatula until just combined.
Pour half of the brownie batter into the prepared pan.
Spread evenly with a small offset spatula.
Bake for 15 minutes or until a toothpick comes out clean.
While the base is baking make the rest of the caramel.
Once the caramels are completely melted and smooth, sift the flour over the top and stir well.
Remove from heat and add the vanilla. Stir well.
Pour the cooked caramel over the HOT brownie base immediately after it comes out of the oven, spread with a spatula.
Dollop the remaining brownie batter over the top and carefully spread over the caramel mixture.
Return to the oven and bake an additional 20 minutes.
Let cool for 15 minutes then glaze.