Preheat oven to 350°F. Generously grease a 12-cup bundt pan with baking spray and dust with cocoa powder.
In a large bowl, whisk together flour, sugar, cocoa powder, baking soda, baking powder, and salt until no lumps remain.
In a separate bowl, beat eggs lightly, then add buttermilk, hot coffee, oil, and vanilla. Mix until combined.
Pour wet ingredients into dry mixture and stir with a spatula until just combined. Batter will be thin.
Transfer batter to prepared pan and smooth the top. Bake for 35-40 minutes until toothpick comes out with moist crumbs.
Cool in pan for 15 minutes, then invert onto wire rack to cool completely before glazing.
For glaze, heat chocolate chips, cream, and butter in saucepan over low heat until melted and smooth. Stir in vanilla.
Pour glaze over completely cooled cake, letting it drip down sides. Let set for 10 minutes before serving.