Preheat the oven to 350 degrees F. Spray a 12-cup bundt pan with baking spray.
For the chocolate cake: In a medium bowl, whisk together the flour, sugar, cocoa powders, baking powder, and salt. Set aside.
In a large bowl, whisk together the milk, oil, eggs, and vanilla.
Add the dry ingredients to the wet and whisk until just combined.
Lastly, whisk in the hot coffee until fully combined. Set aside.
For the pumpkin cake: In a medium bowl, combine the flour, baking powder, baking soda, salt, and pumpkin spice. Set aside.
In a separate large bowl, whisk together the sugars, oil, milk, eggs, and vanilla.
Add the dry ingredients to the wet and whisk until mostly combined. Then, mix in the pumpkin purée until fully combined.
Alternate the cake batters in the bundt pan to create an even swirl.
Bake the cake for 48-52 minutes or until a toothpick inserted comes out clean.
Allow the cake to cool for 10 minutes, then turn out onto a cooling rack to cool completely.
For the glaze: Whisk together the cocoa powder, powdered sugar, and milk. Heat in the microwave for about 15 seconds to bring to a smooth pourable consistency.
Pour the glaze over the cooled cake, then serve.