Preheat the oven to 325°F (convection or standard) and prepare your pan. Spray it with cooking spray and then dust it with flour, tapping the flour around until every inch is covered.
In a medium bowl, whisk together dry ingredients: flour, cocoa powder, baking soda, and salt. In a different bowl, whisk together sour cream and water.
In the large bowl of a stand mixer fitted with the paddle attachment, cream together softened butter and sugars until a thick paste forms. Beat in the eggs one at a time, scraping down the sides of the bowl as you go.
Switch the mixer to low, and alternately add the flour mixture and sour cream mixture. Mix until it is just combined before the next addition.
Add in the vanilla. Turn the mixer speed up so everything incorporates. Your batter will be silky and smooth.
Bake:
Pour into the prepared pan and smooth the top. Bake in a preheated oven until a cake tester or toothpick comes out with a few clinging crumbs. Mine took 70 minutes. Yours could take anywhere between 60-85 minutes depending on your oven.
Let the cake cool for 20 minutes in the pan, and then loosen the edges with a paring knife and turn it out onto a wire rack. Allow the cake to cool completely.
Once the cake is cooled, dust with powdered sugar or drizzle a glaze over the top. After the glaze has set, slice and enjoy!
Notes
Yield: 1, 10-12 cup bundt cakeFlavor Tips – I use dutch processed cocoa powder, which just means it has been treated with an alkaline solution. It has a rich, deep flavor and a darker color than other cocoa powders.Technique – Do not over-cream the butter and sugar. I use butter that is softened but still cool to the touch. Cream the butter and sugars just until a paste forms. Storage – Store chocolate pound cake well wrapped in plastic wrap at room temperature, refrigerated or frozen. Pound cakes will keep 5 days at room temperature, two weeks refrigerated, or 3 months frozen. For optimal freshness, serve within 2 days of baking or freeze for longer term storage.