Preheat oven to 350° F. Generously grease (with Crisco) and flour a bundt pan.
To prepare the cake, combine cake mix, eggnog, vegetable oil, spiced rum and eggs in your mixing bowl and beat on medium speed until smooth. Add nutmeg and vanilla bean paste and gently mix into batter.
Pour batter into bundt pan and spread evenly with a spatula if necessary.
Bake at 350° F for 40-45 minutes. Check for doneness by sticking a toothpick into the middle of the cake. If the toothpick comes out clean, the cake is ready. Remove from oven and allow to cool for 15-20 minutes.
Gently run a knife around as much of the edges as possible, and around the center. Turn your pan over and gently tap until the cake releases. Allow to cool on a wire rack.
To prepare the glaze, sift powered sugar into a medium-sized bowl. Add remaining ingredients and whisk until smooth.
Put wire rack over top of a sheet pan with edges. Pour glaze over top of cake slowly and allow glaze to drip down the sides. Gather excess glaze from the sheet pan by pouring it back into the bowl and pour over top of cake again. Repeat 2-3 more times.