In a pot, melt the butter and salt. Once melted, whisk in the heavy cream and sugar, stirring occasionally until it’s nearly boiling (about 7-8 minutes). Stir in the chocolate chips until melted.

In a stand mixing bowl, sift the cocoa powders. Slowly pour in the hot chocolate mixture and mix until combined. Scrape the bowl and mix for 2-3 minutes until it’s lump-free. Stir in the vanilla, and pour into a container. Refrigerate for at least 4-6 hours, preferably overnight.

Line three 6-inch cake pans with parchment paper and preheat the oven to 350°F (180°C).

In a bowl, whisk together flour, baking soda, and salt until combined. Set aside.

In a separate large bowl, whisk together oil and sugar. Then add buttermilk, eggs, and vanilla extract, whisking well. Mix in the dry ingredients until smooth.

Whisk the hot coffee and black cocoa powder until lump-free. Stir this into the cake batter until just combined.

Evenly distribute the batter among the prepared pans (about 395 grams each). Bake for 25-35 minutes or until a toothpick comes out with a few moist crumbs. Let cool on a wire rack before flipping them out.

When the frosting is at room temperature, mix it briefly to loosen. Place your first cake layer on a serving board and spread a layer of frosting. Continue layering and chilling for 30-60 minutes until firm.

Cover the top and sides of the cake with the remaining frosting. Use a spoon to create swoops for texture. Decorate as desired and enjoy!

Keep leftover slices in an airtight container in the fridge for 4-5 days or wrap and freeze for up to 1 month.