To make the cake: Place the coffee, butter, and cocoa in a small microwave-safe bowl. Microwave in 30 second increments until the butter melts. Whisk until smooth. Let the mixture cool for a few minutes while you do the next steps.
While the chocolate is cooling, put the sugar, baking powder, baking soda, salt, and flour into the bowl of a stand mixer, whisking to combine.
Pour the cooled chocolate mixture into the bowl with the dry ingredients, and mix with a paddle attachment until thoroughly combined. Scrape the bottom and sides of the bowl, and mix again to incorporate any residue.
In the same bowl as the chocolate/butter mixture was in, whisk together the vanilla, eggs, and sour cream or yogurt. Mix into the chocolate batter until combined. Stir in chocolate chips with a spatula.
Thoroughly spray a 10 or 12-cup bundt pan with non-stick cooking spray. Pour the batter into the prepared pan. Bake the cake for 45 to 55 minutes, until a long toothpick inserted into the center comes out clean.
Remove the cake from the oven, wait 5-10 minutes, and turn the pan over onto a cooling rack. Slow lift the pan off the cake. Let the cake cool completely before icing.
For the ganache: Melt chocolate chips and heavy whipping cream in the microwave in 30 second increments until the chocolate is melted. Immediately pour over the top of the cake until the ganache coats the top and runs down the sides. Slice immediately or wait until you're ready to serve.
How to store this cake: Store the bundt cake at room temperature covered. Cake will be fresh for 2-3 days. To freeze: Before frosting, wrap the cake in plastic wrap multiple times. Place in the freezer. To defrost place in the refrigerator overnight, then cover with your ganache and bring back to room temperature before serving.