01 - Preheat the oven to 350°F. Generously grease and flour a 10-cup Bundt pan, ensuring every crevice is coated to prevent sticking.
02 - In a medium bowl, sift together the all-purpose flour, unsweetened cocoa powder, baking powder, baking soda, and salt. Set aside.
03 - In a large mixing bowl, beat the room-temperature butter and granulated sugar together using an electric mixer on medium speed until the mixture is pale, light, and fluffy, approximately 3 minutes.
04 - Add the eggs one at a time, beating thoroughly after each addition until fully incorporated. Blend in the vanilla extract.
05 - Alternately add the sifted dry ingredient mixture and the buttermilk to the butter mixture, beginning and ending with the dry ingredients. Fold gently until just combined—avoid overmixing to keep the crumb tender.
06 - Pour the batter evenly into the prepared Bundt pan, smoothing the surface with a spatula. Bake for 45–50 minutes, or until a wooden skewer inserted into the center comes out clean.
07 - Let the cake rest in the pan for 15 minutes, then carefully invert onto a wire cooling rack. Allow it to cool completely before glazing.
08 - In a small saucepan, heat the heavy cream over medium heat until just steaming—do not boil. Pour the hot cream over the chocolate chips and butter in a heatproof bowl. Let sit for 2 minutes, then whisk until silky smooth.
09 - Drizzle the chocolate glaze evenly over the completely cooled cake, allowing it to cascade naturally down the sides for a dramatic finish.
10 - Lightly dampen the fresh cranberries with water, then roll them in granulated sugar until evenly coated. Allow them to dry on a wire rack. Arrange the sugared cranberries and rosemary sprigs around the top of the cake to mimic a festive wreath. Finish with a light dusting of powdered sugar for a snowy holiday effect.