Instructions

• Preheat the oven to 350 degrees and spray a 9x13 glass baking pan with non-stick spray. Set aside.
• Whisk the buttermilk, eggs, egg yolks, and vanilla in a large bowl until well combined.
• Whisk the flour, sugar, baking soda, baking powder, and salt in a large mixing bowl.
• Add the oil and softened butter and mix with a hand mixer until well combined. Then, add the egg and buttermilk mixture.
• Mix with a hand mixer, the color lightens, and it becomes fluffy.
• Pour the batter into the pan and bake for 26 to 30 minutes until a toothpick inserted into the center comes out clean or with dry crumbs.
• Remove the pan and place it on a wire rack. Cool completely.
• Melt the dark chocolate chips or chopped dark chocolate in the microwave at 20-second intervals until melted and smooth.
• Add all the frosting ingredients except the melted chocolate to a large mixing bowl.
• Mix with a hand mixer on low speed for about a minute. Then, turn the speed to medium and mix for another minute until fully combined.
• Mix the melted chocolate with a whisk until shiny, then add to the frosting and mix again for another 30 seconds until smooth.
• Cover the bowl with parchment paper and let it set for about 35 minutes.
• When the cake is thoroughly cooled, top it with the fudge frosting and enjoy!