01 - Preheat the oven to 350°F (175°C). Generously grease and flour a 10-inch Bundt pan, ensuring every crevice is coated to prevent sticking.
02 - In a large mixing bowl, whisk together the all-purpose flour, unsweetened cocoa powder, baking powder, baking soda, and salt until evenly distributed and no lumps remain.
03 - Using a stand mixer fitted with the paddle attachment or a hand mixer, beat the softened unsalted butter and granulated sugar on medium-high speed until pale, light, and fluffy, approximately 3 to 4 minutes.
04 - Add the eggs one at a time, beating well after each addition to maintain a smooth emulsion. Blend in the vanilla extract until fully incorporated.
05 - With the mixer on low speed, add the dry ingredient mixture alternately with the sour cream and whole milk in three additions, beginning and ending with the dry ingredients. Mix just until combined — do not overmix.
06 - Pour the batter into the prepared Bundt pan, using a spatula to smooth the top and ensure even distribution throughout the pan's decorative ridges.
07 - Bake on the center rack for 45 to 50 minutes, or until a wooden toothpick inserted into the thickest part of the cake comes out clean. The cake should spring back lightly when pressed.
08 - Allow the cake to cool in the pan for 10 minutes, then carefully invert onto a wire cooling rack. Let the cake cool completely before decorating, approximately 1 hour.
09 - In a small saucepan, heat the heavy cream over medium-low heat until it just begins to simmer — do not boil. Pour the hot cream over the semi-sweet chocolate chips in a heatproof bowl and let stand for 2 minutes. Stir gently from the center outward until a smooth, glossy ganache forms. Allow to cool slightly until it reaches a thick drizzling consistency.
10 - Spoon or drizzle the ganache evenly over the fully cooled Bundt cake, allowing it to cascade naturally down the sides for an elegant finish.
11 - Arrange candied cherries, cranberries, and green candied fruit around the top ring of the cake to resemble a festive wreath. Tuck small sprigs of fresh rosemary or mint between the fruit for a natural holly effect. Finish with a light dusting of powdered sugar to mimic fresh snow.