First, preheat your oven to 350ºF (177ºC) and move your oven rack so that it is lower in the oven.
Prepare your bundt pan with cake goop or another preferred pan release.
Then, sift your flour, cocoa powder, baking powder, baking soda, and salt together in the bowl of your standing mixer so you don’t have any lumps in your final batter.
In another mixing bowl, combine your room temperature buttermilk, vegetable oil, coffee, and vanilla together and then set it aside. Next, cream your room temperature butter until it’s smooth. Then, add in your sugars and cream the butter with the sugars on medium speed (speed 2 on a Bosch mixer, speed 4 on a KitchenAid) until it is light and fluffy.
Add in your eggs one at a time. Make sure the eggs are room temperature or your batter may curdle and separate.
Then, add in 1/3 of your flour while mixing on low, and then add 1/3 of your liquids. Repeat two more times until everything is mixed together, and then stop mixing.
Stir in your mini chocolate chips if desired.
Pour your batter into your prepared bundt cake pan and bake the cake for 45-55 minutes (or until a skewer comes out with only a few sticky crumbs attached to it).
Once the pan is cool to the touch, carefully flip the cake out onto a cooling rack.
Let the cake cool uncovered for two hours before you add chocolate glaze.