In a medium mixing bowl, whisk together the flour, baking powder, cocoa and salt. Set aside.
In the bowl of a stand mixer fitted with the paddle attachment, beat the butter and sugar until light and fluffy. Add the eggs, one at a time, beating just until the yellow yolk disappears. Beat in the vanilla until blended. Add the flour mixture alternatively with the buttermilk and espresso liquid, beginning and ending with the flour mixture.
Spray the Bundt pan with a non-stick baking spray such as Pam with flour. Pour the batter into the prepared Bundt pan and spread evenly.
Bake for 60 minutes or until a toothpick inserted into the center of the cake comes out clean. Allow the cake to cool for about 30 minutes then remove from the pan and invert onto a wire rack to finish cooling.
Once cooled dust with sifted powdered sugar, chocolate glaze or icing.
To prepare the satiny chocolate glaze:
Place a heat proof bowl over a pan of hot but not boiling water. Add the butter, chocolate chips and corn syrup. Heat and stir until the chocolate is melted and smooth. Add the vanilla and stir well. Drizzle over the cake and serve