Dulce de Leche Swirl S'mores Brownies (Guest Post from Melanie Makes)

Ingredients (16)

• 14 ounces sweetened condensed milk
• 3 cups graham cracker crumbs
• 1/4 cup sugar
• 1/4 teaspoon salt
• 3/4 cup butter, melted
• 3/4 cup cocoa
• 3/4 cup butter, melted
• 2 Tablespoons hot water
• 1-2/3 cup sugar
• 2 eggs, beaten
• 2 teaspoons vanilla
• 1-1/3 cup flour
• 1/2 teaspoon baking powder
• 1/4 teaspoon salt
• 2 cups chocolate chips
• 10-1/2 ounces mini marshmallows