Preheat the oven to 325 degrees F. Spray a 10-cup bundt pan with nonstick baking spray. Set aside.
Chop up the chocolate into small bits, about 1/2 inch pieces, then set aside. This doesn't have to be perfect. 6 oz Bittersweet Chocolate
In a large bowl, combine melted butter, vegetable oil, sugar, and brown sugar. Whisk together for about 1 minute, until the sugar begins to dissolve. Add eggs, egg yolk, sour cream, and vanilla extract and continue to mix until combine. 3/4 cup Salted Butter1/3 cup Vegetable Oil1 cup Sugar2/3 cup Brown Sugar 3 large Eggs1 Egg Yolk1 cup Sour Cream1 tbsp Vanilla Extract
Sift in all purpose flour and cocoa powder (this prevents lumps from forming), then add baking soda, and kosher salt. Whisk everything together until just combined, then pour in the hot coffee. Whisk until the coffee is incorporated, then fold in the chopped chocolate. 1 2/3 cups All Purpose Flour3/4 cup Natural Cocoa Powder1 tsp Baking Soda1/2 tsp Kosher Salt 3/4 cup Coffee
Pour the cake batter into the prepared pan and bake in the oven for 55-65 minutes, until a toothpick inserted into the center of the cake comes out with a few moist crumbs.
Now make the chocolate ganache - add a cup of heavy cream to a microwave-safe bowl. Heat in the microwave for about 1 minute, until hot. Add the semi-sweet chocolate chips and butter. Let it sit for 2 minutes, then whisk together until combined.
Pour on top of the cooled brownie cake and enjoy.
Notes
Sift cocoa and flour together. Cocoa loves to clump. Sifting prevents bitter pockets and gives you a finer, silkier crumb.
Pull it from the oven when you the skewer comes out with moist crumbs, not clean. Clean skewer means it's overbaked. You want just a few moist crumbs coming out - this is key to that super fudgy texture and moist chocolate cake.
Use quality chocolate! For that deep chocolate flavor, using quality baking chocolate is key! I used Guittard's baking chocolate - it lends a decadent flavor that's key to getting this cake to taste like a brownie.