01 - Preheat oven to 350°F. Grease and flour a 10-cup Bundt pan thoroughly, 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 using an electric mixer until light and fluffy, approximately 3 minutes.
04 - Add the eggs one at a time, beating well after each addition. Blend in the vanilla extract until evenly distributed.
05 - Alternately add the sifted dry ingredients and buttermilk to the butter mixture, beginning and ending with the dry ingredients. Mix until just combined — avoid overmixing to maintain a tender crumb.
06 - Pour the batter evenly into the prepared Bundt pan and smooth the top with a spatula.
07 - Bake for 45–50 minutes, or until a wooden skewer inserted into the center of the cake comes out clean.
08 - Allow the cake to cool in the pan for 15 minutes, then invert onto a wire rack and let cool completely before glazing.
09 - In a small saucepan, heat the heavy cream until just steaming. Pour it over the chocolate chips and butter in a heatproof bowl. Let sit for 2 minutes, then whisk until smooth and glossy.
10 - Drizzle the chocolate glaze over the fully cooled cake, allowing it to flow naturally down the sides.
11 - Lightly dampen the fresh cranberries with water, then roll them in granulated sugar to coat. Let them dry on a wire rack. Arrange the sugared cranberries and rosemary sprigs on the cake to resemble a festive wreath. Dust lightly with powdered sugar for a snowy finish.