Instructions

• Preheat the oven to 325°F and position a rack in the center of the oven. Grease a 10- or 12-cup bundt pan with butter and lightly flour it, tapping out any excess flour. Set the pan aside.
• In a medium bowl, dissolve 1 tablespoon instant coffee granules in 1/4 cup hot water, stirring until dissolved.
• Stir 1 1/3 cups buttermilk and 8 oz melted (and lightly cooled) chocolate into the dissolved coffee mixture. Set this liquid mixture aside.
• In the bowl of a stand mixer fitted with the paddle attachment, beat 1 1/2 cups room-temperature butter, 2 cups granulated sugar, and 1/2 cup brown sugar on medium speed until light and fluffy, about 4–5 minutes. Scrape down the sides and bottom of the bowl as needed.
• With the mixer on medium-low, add 5 large room-temperature eggs one at a time, mixing until just combined after each egg. Stop and scrape the bowl between additions.
• Add 1 tablespoon vanilla extract and mix briefly to combine.
• In a separate medium bowl, whisk together 2 cups all-purpose flour, 3/4 cup unsweetened cocoa powder, 1 teaspoon baking powder, and 1 teaspoon kosher salt.
• With the mixer on low speed, add the flour mixture and the buttermilk-coffee-chocolate mixture to the butter mixture in alternating additions, beginning and ending with the flour mixture (about 3–4 additions total). Mix only until each addition is incorporated; stop to scrape the bowl a few times and do not overmix.
• Using a rubber spatula, fold in 1 cup chocolate chips until evenly distributed.
• Pour the batter into the prepared bundt pan and smooth the top. Bake in the preheated oven for 60–70 minutes, or until a toothpick inserted into the center comes out clean or with just a few moist crumbs (not raw batter).
• Remove the cake from the oven and cool in the pan on a wire rack for 15–20 minutes. Run a butter knife around the edges to loosen the cake, invert the pan onto the rack, and remove the pan. Let the cake cool completely on the rack.
• Once the cake is completely cooled, dust with powdered sugar or top with chocolate ganache before serving.