Position the rack in the center of your oven and preheat it to 350ºF. This temperature is crucial for achieving that perfect bake.
Prepare your Bundt cake pan by generously buttering and flouring it. Make sure to tap out the excess flour. Sprinkle caster sugar evenly on the bottom of the pan to create a sweet crust.
In a medium bowl, whisk together flour, baking powder, salt, and baking soda. This mixture will provide the structure for your cake.
In a separate small bowl, combine sour cream and milk, whisking until smooth. This wet mixture will add moisture to your cake.
Sift cocoa powder into another small bowl. Whisk in honey and boiling water until smooth. Let this mixture cool completely; it will become a rich chocolate base.
In a large bowl, use an electric mixer to beat sugar and unsalted butter until the mixture is light and fluffy, about three minutes. This process incorporates air, which is important for a light texture.
Add the eggs one at a time, beating well after each addition. Be sure to scrape down the sides of the bowl to ensure everything mixes evenly. Once incorporated, add vanilla extract.
Stir in the cooled cocoa mixture, blending until smooth. Scrape down the bowl as needed to avoid any lumps.
Gradually add the flour mixture to the batter, alternating with the sour cream mixture, doing this in two additions. Mix until just blended; overmixing can lead to a tough cake.
Gently fold in the bittersweet chocolate chips and dried cranberries, ensuring they are evenly distributed throughout the batter.
Transfer the batter to the prepared Bundt pan and smooth the top with a spatula. This ensures an even rise while baking.
Bake for about one hour, or until a tester inserted into the center comes out clean. The cake should spring back when lightly pressed.
Once baked, remove the cake from the oven and let it cool in the pan for about 10 minutes. Carefully invert it onto a wire rack to cool completely.
Before serving, sprinkle with powdered sugar for a beautiful presentation.
