Heat the oven to 325ºF.

Prepare a 9x13 pan with parchment paper, set aside. 

In a medium saucepan, melt the butter over medium heat. Whisk in the cocoa powder until smooth. Then add the sugar, and oil. Whisk over medium heat until the sugar begins to melt. The mixture should not come to a simmer. 

Remove the pan from the heat and stir in the vanilla extract, eggs, followed by the salt, baking powder and Argo Corn Starch until combined. Stir the flour in last – taking care to not overstir. 

Fold in the chocolate chips and pour the batter into the prepared pan. 

Top the brownie batter with caramel sauce in about 6 dollops. Drag a knife through the batter and caramel to swirl the sauce. Top with the pretzels and semi-sweet chocolate chips, if using. 

Bake for 35 to 37 minutes. The brownies are done when a toothpick comes out with a firm bit of brownie attached. The brownies will continue to cook as the pan cools. 

Cool brownies completely before cutting.