Velvet Brownie Swirl Cake

INGREDIENTS

• For the Velvet Cake:
• 1 1/2 cups vegetable oil
• 1 1/3 cups buttermilk, room temperature
• 3 eggs, room temperature
• 1 1/2 tsp. white vinegar
• 1 1/2 tsp. vanilla extract
• 3 1/2 cups all purpose flour
• 2 1/4 cups granulated sugar
• 1 tsp. baking soda
• 1 tsp. baking powder
• 1 tsp. salt
• 4 tsp. unsweetened cocoa powder
• For the Brownie Swirl:
• 3 Tb. unsweetened cocoa powder
• 4 oz. bar chocolate, chopped and melted
• For the Vanilla Glaze:
• 6-9 Tb. heavy cream
• 2 cups powdered sugar
• 1 Tb. vanila bean paste (or extract)