Pumpkin-Black Cocoa Swirl Cake

Preheat the oven to 350 degrees F (175 degrees C). Thoroughly spray a 12-cup Bundt pan with baking spray that contains flour (e.g., Baker's Joy®). This ensures the intricate design releases cleanly. (5 minutes)

In a large bowl, whisk together the flour, pumpkin pie spice, baking powder, baking soda, and salt. Whisking ensures even distribution and avoids clumps. (3 minutes)

In a separate large bowl, cream together the softened butter, oil, and 2 cups of white sugar with an electric mixer on medium-high speed until light and fluffy (about 3 minutes). This step is crucial for incorporating air and creating a tender crumb. Add the eggs one at a time, beating well after each addition. Continue beating on medium-high speed until the mixture has doubled in volume (about 5 minutes). This creates a stable emulsion. Incorporate the pumpkin puree and vanilla extract until just combined. Reduce the mixer speed to low and gradually add half of the dry ingredients, mixing until just combined. Add the sour cream, mixing until just combined, followed by the remaining dry ingredients, mixing until just combined. Be careful not to overmix, as this can lead to a tough cake. (15 minutes)

In another bowl, measure out 3 cups of the pumpkin batter. Add the black cocoa powder, unsweetened cocoa powder, 2 tablespoons of sugar, milk, espresso powder (if using), and the melted semi-sweet chocolate to this portion of the batter. Mix on low speed until evenly combined. This creates the striking black cocoa swirl. (5 minutes)

Evenly spread one-third of the black cocoa batter into the bottom of the prepared Bundt pan. Gently pour half of the plain pumpkin batter over the black cocoa layer. Add another one-third of the black cocoa batter over the pumpkin batter. Layer the remaining half of the plain pumpkin batter on top, and finish with the remaining one-third of the black cocoa batter. (10 minutes)

Bake in the preheated oven for 60 to 65 minutes, or until a bamboo skewer inserted into the center comes out mostly clean. A few moist crumbs are fine, but the skewer should not be wet with batter. Let the cake cool in the pan for 25 to 30 minutes before inverting it onto a wire rack to cool completely. This prevents the cake from breaking during removal. (60-65 minutes baking, 25-30 minutes cooling)

To prepare the icing, combine the powdered sugar, 2 tablespoons of black cocoa powder, vanilla extract, and a pinch of salt in a bowl. Gradually whisk in the heavy cream, starting with 6 tablespoons, until you reach a smooth, drizzling consistency. Drizzle the icing evenly over the cooled cake. (5 minutes)