Start by making bundt cake first: Preheat oven to 350 degrees. Grease a 10-12 cup bundt pan. Set aside.
In a medium bowl, whisk together all the dry ingredients; flour, ginger, cinnamon, allspice, cloves, salt, baking soda and baking powder. Set aside.
In a large bowl, whisk together brown sugar, oil, molasses, eggs and vanilla extract. Mix until you see no lumps. Pour in the buttermilk and whisk until smooth.
Add the dry flour ingredients to the wet ingredients in two additions, whisking until the flour is absorbed. Transfer the batter to the bundt ban.
Bake at 350 for 40-45 minutes or until a toothpick inserted in the center comes out clean.
Allow the cake to cook on a wired rack for about 10 minutes. Then invert on to wire rack and cool completely before adding glaze.
Finish by making eggnog glaze: In a small bowl, combine the confectioners sugar and the eggnog. Stir until smooth. Add a drop more eggnog at a time until you get the desired glaze consistency. Drizzle over top of bundt cake.