Mississippi Mud Brownies

My favorite one-bowl brownie recipe topped with warm gooey marshmallows and chocolate frosting

Ingredients
For the brownies:

• 1/3 cup unsweetened cocoa powder
• 1/2 cup oil (vegetable or canola oil)
• 1/2 cup butter , softened
• 2 cups granulated sugar
• 4 large eggs
• 2 teaspoons vanilla extract
• 1 1/2 cups all-purpose flour
• 1 teaspoon salt
• 3 cups mini marshmallows

For the frosting:

• 1/2 cup melted butter
• 1/3 cup unsweetened cocoa powder
• 1/3 cup evaporated milk
• 1 teaspoon vanilla extract
• 3 - 3 1/2 cups powdered sugar

Instructions

• Preheat oven to 350 degrees F. Grease a 9x13'' pan with non-stick cooking spray.
• In a large mixing bowl, pour oil over cocoa powder and mix. Add softened butter and mix until smooth. Add sugar and mix for 1 minute. 
• Add eggs, one at a time, mixing after each addition. Add vanilla and mix. Add flour and salt and stir to combine. 
• Pour batter into prepared pan. Bake for 25-30 minutes or until a toothpick inserted into the center comes out clean.
• Remove brownies from the oven and sprinkle the marshmallows evenly on top. Return to the oven for 2-3 minutes or until the marshmallows are puffed. Remove from oven and allow them to cool completely.
• Once brownies are cool, make the frosting.

For the frosting:

• Add melted butter, cocoa powdered, evaporated milk, vanilla, and 2 cups of powdered sugar to a mixing bowl and beat with electric beaters until smooth. 
• Add more powdered sugar, a cup at a time, mixing well, until you reach your desired frosting consistency. I usually use about 3 1/4 cups powdered sugar.
• Spread frosting over the cooled brownies and cut into squares. I've found a plastic knife works best to cut them, or if you make them 1 day in advance they are much easier to cut.
• Have you tried Mississippi Mud Cake?