Preparation Steps

• Heat the oven to 340°F. Generously butter a 10- to 12-cup Bundt pan and dust with cocoa powder (not flour) to prevent pale streaks. Tap out the excess.
• Bloom the cocoa: In a heatproof bowl, whisk the cocoa with the hot coffee until smooth and glossy. Let stand 3 minutes to intensify the chocolate flavor.
• Whisk the dry ingredients in a separate bowl: flour, baking powder, baking soda, salt, and cinnamon.
• In a large mixing bowl, whisk together the sugar and oil until the sugar looks slightly damp. Add the eggs one at a time, whisking well after each, then mix in the vanilla. Whisk in the sour cream and milk until completely smooth.
• Stream the warm cocoa–coffee mixture into the bowl and whisk just until evenly combined and dark.
• Switch to a spatula and fold in the dry ingredients in two additions, stopping as soon as you no longer see dry flour. Let the batter rest 8–10 minutes to hydrate for a more tender crumb.
• Scrape the batter into the prepared pan and tap firmly on the counter to release air bubbles. Bake 38–44 minutes, rotating the pan once after 25 minutes, until a skewer inserted near the center comes out with a few moist crumbs.
• Cool the cake on a rack for 12 minutes. Loosen edges with a thin spatula, invert onto the rack, and cool completely (about 1 hour) before glazing.
• Make the ganache: Place chopped chocolate in a medium bowl. Heat the cream until steaming but not boiling; pour over the chocolate, add the pinch of salt, and let sit 2 minutes. Whisk from the center outward until smooth and glossy; cool 5–10 minutes until slightly thickened but still pourable.
• Set the cooled cake on a rack over a sheet pan and spoon the ganache over the top, letting it cascade down the ridges. Let set 15 minutes before slicing.