Preheat oven to 350 degrees Fahrenheit and grease (well) and lightly flour a 10 in. fluted bundt cake pan.
For the pumpkin cake, in the bowl of an electric mixer, cream together sugar, canola oil, and eggs. Add pumpkin and mix well.
In a separate bowl, stir together flour, baking soda, cinnamon, nutmeg, salt, and cloves. Add to pumpkin mixture and mix well. Set aside for a minute while you prepare the chocolate marble.
For the chocolate marble, in the bowl of an electric mixer, cream together cream cheese, egg, sugar and salt. Add melted chocolate chips and mix until smooth and creamy.
Pour 1/2 of the chocolate mixture into the bottom of the bundt cake pan and spread around evenly. Next, pour 1/2 of the pumpkin mixture over that and spread evenly around. Pour remaining half of the chocolate mixture over that and spread around evenly. Lastly, spread the last 1/2 of the pumpkin batter around.
Bake for approximately 60 minutes (mine was done in 56 minutes), or just until a toothpick inserted into the center comes out clean. Allow it to cool for 10 minutes in the bundt cake pan before carefully inverting it onto a wire cooling rack. Cool completely.
Prepare the glaze by whisking together powdered sugar and milk in a bowl. Drizzle over cooled cake and serve.