Preheat oven to 350°F/175°C. Generously grease and flour a 12-cup bundt cake pan, being sure to cover the entire inside of the pan.
Combine flour, sugar, cocoa, baking powder, baking soda, salt, and coffee in a large bowl.
In a separate bowl, combine water, yogurt, vegetable oil, vinegar, and vanilla. Stir to combine.
Pour the wet ingredients in with the dry mixture. Stir until mostly combined. Then use a wire whisk to stir for up to another minute, until all lumps of flour are gone.
Pour the thick batter equally around the prepared pan. Smooth the top with a spatula. Bake for 50 - 60 minutes, until a tester inserted in the center comes out clean.
For the Chocolate Glaze:
While the cake bakes, prepare the chocolate glaze. Combine chocolate and creamer in a microwave-safe bowl. Heat in the microwave for one minute. Then cover and let it sit for 2 to 3 minutes. Stir together until creamy and smooth. If the chocolate is not melted, heat in 20-second increments until melted.
When the cake is done, remove it from the oven. Set a timer for 15 minutes to allow the cake to cool slightly, then place a plate or wire rack over the top and then flip it (invert) to remove it from the bundt pan. Set the cake aside to cool.
Once the cake is cool, top with drizzles of the chocolate glaze.
Store the cake at room temperature for 2 to 3 days or in the fridge for up to 10 days. Individual slices can be frozen in freezer-safe containers for up to 2 months.
Notes
Flour
I use a combination of 2 cups all-purpose flour with 1 cup whole wheat flour. You can use 100% all-purpose flour, or a mixture like I did. See my guide for using whole wheat pastry flour in baked goods. Or, substitute a baking-quality gluten-free flour.
Yogurt
Here are some substitution ideas for plain vegan yogurt:
Vegan sour cream — This is a great substitute for vegan yogurt.
I used the fat scooped from the top of a chilled can of coconut milk. You can also substitute vegan creamer, or vegan half and half (Ripple is a popular brand). Or, use soy milk with a tablespoon of coconut oil (to add richness).