Preheat the oven to 350 F (177 C). Grease a 10 -inch (12 cup capacity bundt pan) with nonstick spray. Use a pastry brush to work the nonstick spray into all the grooves of the pan.
In a large bowl, whisk the flour, Dutch processed cocoa powder, baking powder, baking soda, salt nutmeg or cardamom and instant espresso powder together until well combined.
2¾ cup (330 g) all purpose flour, ¾ cup (60 g) Dutch processed cocoa powder, 2 teaspoons baking powder, 1 teaspoon salt, 1 teaspoon instant espresso powder, ½ teaspoon baking soda, ½ teaspoon ground nutmeg or cardamom
In the bowl of a stand mixer fitted with paddle attachment, cream the butter, sugar and light brown sugar together until light, fluffy and well combined. This takes about 2 - 3 minutes at medium speed. Scrape the sides and bottom of the mixing bowl.
1 cup (226 g) unsalted butter, room temperature, 1¼ cup (250 g) granulated sugar, ½ cup (100 g) light brown sugar
On low mix in the eggs and vanilla extract one at a time, waiting until the previous ingredient is just combined before adding the next. Mix until well combined. By hand or on the lowest mixing speed, mix the dry ingredients into the wet alternating with the buttermilk and sour cream until the batter is just combined. Gently stir in the hot water until well mixed into the chocolate cake batter. Evenly scoop the chocolate donut cake batter into the prepared bundt pan. 3 large eggs, room temperature, 2 teaspoons vanilla extract , ¾ cup (180 ml) buttermilk, room temperature, ¼ cup (60 g) sour cream, room temperature, ½ cup (120 ml) hot water or coffee
Bake the donut chocolate cake for 45 - 50 minutes or until a toothpick inserted into the center of the pound cake comes out with a few moist crumbs.Cool the cake in the pan for 10 minutes. Invert the bundt cake pan onto another cooling rack or plate. Then flip the cake upside down one more time so the top is facing up again. Cool the cake completely before topping or serving. Make the vanilla glaze by whisking the powdered sugar with water or coffee, milk and vanilla extract. Pour the glaze on top of the cooled cake donut. Use a pastry brush to apply the glaze to the sides of the cake. Allow 30 - 45 minutes for the glaze to fully set, slice and enjoy. 2 cups (240 g) powdered sugar, 2 tablespoons (30 ml) water or coffee, 2 tablespoons (30 ml) milk, 1 teaspoon vanilla extract