Prepare the oven and grease the pan. Preheat oven to 350°F. Grease the mini bundt pan.
Whisk the dry ingredients. In a large bowl, whisk together sugar, cocoa powder, flour, baking soda, baking powder, and salt.
Whisk the wet ingredients. In a separate bowl, whisk oil, vanilla, eggs, and buttermilk.
Combine the wet and dry ingredients. Pour the wet ingredients into the dry, whisking until no lumps remain. Pour in room temperature Vietnamese coffee and mix until just combined.
Pour batter into prepared pan and bake at 350°F for 20-25 minutes, or until a toothpick inserted in the cake comes out clean (with a few crumbs on it). Let the cakes cool on a drying rack in the pan for 15 minutes before removing them from the pan. Cool the cakes completely before adding the ganache.
Make the Ganache. In a saucepan on medium heat, bring heavy cream to a simmer, stirring occasionally. Next, remove from heat and pour chocolate chips into the pan. Place lid on chocolate chips and let sit without mixing for 5 minutes. Lastly, mix until combined. Let the ganache sit uncovered for 15 minutes or until it is room temperature before pouring it over your cakes. [mv_img id="1338"]