1. Preheat your oven to 350*F with a rack in the center. Grease an 8”x4” loaf pan and line the bottom and sides with parchment.
2. Into the bowl of your stand mixer fitted with the paddle attachment, combine the flour, sugar, baking powder and salt, whisk to combine.
3. To the dry ingredients add the heavy cream, vegetable oil, buttermilk, eggs and vanilla.
4. Mix on low until combined and then mix at medium/high speed for 2 minutes. Scrape the bowl and then mix on low speed for 30 seconds more.
5. Measure one cup of vanilla batter into a bowl and whisk in the 2 tablespoons cocoa powder and 1 teaspoon water until smooth.
6. Add about ⅓ of the vanilla batter to the loaf pan then add ⅓ of the chocolate batter in a line down the center of the vanilla batter. Continue layering the batters until all of the batter is in the pan.
7. Bang the pan firmly on the counter 4-5 times to remove air bubbles.
8. Bake the loaf cake for 60-65 minutes or until a toothpick inserted in the center comes out with a few moist crumbs. Cool on a cooling rack for 20 minutes before removing the cake to cool on the rack completely, about 2-2.5 hours.
9. To make the fudge frosting, add the chocolate chips and vegetable oil to a microwave safe bowl.
10. Melt the chocolate chips and vegetable oil in 15 second increments, stirring until smooth, about 30 seconds total.
11. In your stand mixer bowl cream the butter at medium speed until smooth and shiny. Scrape the bowl.
12. Add the cocoa, confectioners sugar, salt, vanilla and 2 tablespoons heavy cream along with the warm chocolate. Mix on low to combine then on medium speed for one minute. If the frosting seems too thick add the additional tablespoon of cream. Scrape the bowl and paddle attachment and mix on low for another minute.
13. Using a serrated knife slice the loaf cake in half horizontally. Spread about ½ of the frosting onto the bottom layer of the cake, add the top half of cake and spread on remaining frosting.