Preheat your oven to 350°F and generously grease a Bundt pan (12-cup capacity), making sure to coat all the crevices so the cake releases cleanly. Finely chop the chocolate into 1/4-inch pieces and set aside in a bowl—uniform pieces melt more evenly and create a silkier glaze. Sift the cocoa powder to remove any lumps, which will ensure a smooth batter without grittiness. Have all remaining ingredients measured and ready, with eggs brought to room temperature for better emulsification.

Pour the 12 oz stout into a pot and bring it to a gentle simmer over medium heat for about 1-2 minutes to reduce the carbonation slightly and concentrate the flavor. Remove from heat and stir in the sifted cocoa powder and espresso powder, whisking until completely smooth with no cocoa lumps remaining. Let this mixture cool to room temperature (about 10-15 minutes)—this prevents the eggs from cooking when you combine them later. I like using Guinness Draught specifically because its deep roasted notes complement the cocoa beautifully.

In one large bowl, whisk together the flour, sugar, baking soda, salt, and cinnamon until evenly distributed. In a second bowl, whisk the room-temperature eggs, oil, buttermilk, and vanilla until the mixture is pale and slightly emulsified—this incorporates air and helps create a tender crumb. Keeping wet and dry separate at this stage allows for better control and prevents overmixing, which would toughen the cake.

Pour the cooled beer-cocoa mixture from Step 2 into the wet ingredient mixture from Step 3, stirring until well combined. Add this combined wet mixture to the dry ingredients from Step 3 and fold together gently until just combined—do not overmix, as this develops gluten and results in a dense cake. The batter should be smooth and pourable with no visible dry streaks. I find using a spatula and folding from the bottom up keeps the batter tender.

Pour the batter from Step 4 into the prepared Bundt pan and smooth the top gently. Bake at 350°F for 45-50 minutes, until a toothpick inserted into the center comes out with just a few moist crumbs (not wet batter). The cake will rise nicely and the top should spring back when lightly touched. Let cool in the pan for 15 minutes, then invert onto a wire rack to cool completely before glazing—this prevents the cake from being too warm when the ganache is applied.

Heat the cream in a small pot until it just reaches a simmer (small bubbles around the edges). Pour the hot cream over the finely chopped chocolate from Step 1 in a bowl and let sit undisturbed for 1 minute—this allows the heat to soften the chocolate evenly. Add the whiskey, vanilla, and salt, then stir gently until the mixture is completely smooth and glossy. Let the glaze cool at room temperature for about 5-10 minutes so it reaches a pourable but not-too-thin consistency.

Once the cake is completely cooled and the glaze is at the right consistency (pourable but slightly thickened), pour it slowly over the center of the Bundt cake, allowing it to flow naturally down the sides and fill the crevices. Let the glaze set at room temperature for 1-2 hours until it firms up to a fudgy consistency—don't refrigerate, as this can make the glaze too firm and dull its shine. The cake can be sliced and served once the glaze has set, and it actually tastes even better the next day when the flavors have melded together.