01 - Preheat 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, cocoa powder, baking powder, baking soda, and salt. Set aside.
03 - In a large bowl, beat the room-temperature butter and granulated sugar with an electric mixer until pale, light, and fluffy, approximately 3 minutes.
04 - Add the eggs one at a time, beating thoroughly after each addition until fully incorporated. Stir in the vanilla extract.
05 - Alternately add the sifted dry ingredients 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 top with a spatula to ensure even distribution.
07 - Bake on the center rack for 45–50 minutes, or until a wooden skewer inserted into the thickest part of the cake emerges clean.
08 - Let the cake rest in the pan for 15 minutes to set, then carefully invert onto a wire cooling rack. Allow to cool completely before glazing.
09 - In a small saucepan, heat the heavy cream over medium-low 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 glossy and smooth.
10 - Drizzle the warm glaze over the completely cooled cake, letting it flow naturally down the sides for a cascading effect.
11 - Lightly dampen the fresh cranberries with water, then roll them in granulated sugar until evenly coated. Arrange on a wire rack to dry. Place the sugared cranberries and rosemary sprigs artfully around the top of the cake to resemble a wreath. Finish with a light dusting of powdered sugar for a snowy finish.