In a large Saucepan over medium heat add ½ Cup Butter, Vegetable Oil, water, and Coco Powder.
Use a whisk to blend and bring to a boil.
In a separate bowl combine dry ingredients: Flour, Sugar, Salt and Baking Soda
When mixture comes to a boil turn off heat and add SIFTED flour mixture and stir to combine.
Stir in Buttermilk, eggs and Vanilla
Pour mixture into Jelly Roll pan and bake at 350 20-22 minutes
Frosting
In a saucepan over medium heat add ½ cup Butter, milk and vanilla.
Sift Powdered Sugar and Coco Powder into a bowl
With butter melted add powdered sugar and coco and stir until smooth
Pour warm frosting on hot brownies and spread with rubber spatula.
Allow to cool
Whipping Cream
In a chilled bowl add Heavy Whipping Cream and whip with hand mixer until soft peaks form
Add powdered sugar and vanilla and continue to whip until stiff peaks form
Notes
How to Make Buttermilk:
Add 1 ½ teaspoon Vinegar to ½ Cup Measuring cup. Fill remaining with milk and allow to sit for 10 minutes. Milk will curdle and works perfectly to substitute in recipes.