Measure out the heavy whipping cream and put it in the freezer for 10 minutes to get it very cold. Stir together the vanilla and rum and chill in the freezer.

In the bowl of a stand mixer fitted with the paddle attachment, whip the heavy cream until stiff peaks begin to form, about 5 minutes. Scrape down the sides with a rubber spatula.

Add powdered sugar and rum mixture and whip an additional 2 minutes. Put in the fridge until ready to assemble cocktails.

In a stand mixer, blend the butter, sugar, cinnamon and nutmeg until completely smooth.

Add 1½ Tbsp of butter mixture on bottom of drinking glasses. Add approx. 4 oz of dark rum and top glass off with hot water. Stir until butter mixture is mostly dissolved.

Top with chilled rum-infused whipped cream and serve immediately. Cheers!