Preheat oven to 350F. Brush 2 6-inch round cast iron pans lightly with melted butter
In a medium bowl, whisk melted butter corn oil and sugar until smooth. Add egg and water, whisk until blended.
Sift flour and KESSLER’S® Alkalized Cocoa Powder over the butter mixture, then gently stir with a wire whisk until there are no more dry streaks. Divide batter between the 2 cast iron pans.
Bake for 28 to 30 minutes or until top looks set and toothpick inserted in the middle is not wet but has crumbs sticking to it when taken out.
Remove from the oven. Stick graham crackers, chocolate bars and marshmallows on top of the brownie. You can torch the marshmallows or place the pan in a preheated oven toaster to toast the marshmallows.