Preheat oven to 350 degrees Fahrenheit. Use butter to grease a 10-12 cup bundt pan well. Dust with a little flour or cocoa powder and tap out the excess.
Mix together flour, sugar, cocoa, baking soda, baking powder, and salt in a large mixing bowl until combined.
Add eggs, warm water, buttermilk, sour cream, oil, and vanilla. Use a hand mixer to beat on a medium speed until smooth. This should take just a couple of minutes.
Pour batter into prepared bundt pan. Tap the pan on the countertop a few times to allow any air bubbles to escape.
Bake for 45-50 minutes in a 350 degree oven until a toothpick inserted into the center comes out clean.
Cool on a wire rack for 15 minutes and then turn out onto the racks and allow to cool completely.
Chocolate Ganache Glaze
Place roughly chopped chocolate into a mixing bowl. Pour heavy cream into a small saucepan and bring it to a simmer over medium heat.
Once cream comes to a simmer, remove it from the heat immediately and pour over chocolate. Let stand 5 minutes, until chocolate is completely melted.
Stir until smooth. Once smooth, stir in corn syrup. Drizzle over the top of the cooled cake.