Serves 10-12 (6 oz pours).
Place the mace, allspice berries, cloves and cinnamon on top of a square of cheesecloth, and use kitchen twine to tie tightly into a spice sachet.
Turn a crockpot on high. Add the cream and eggs, and whisk until homogenized. Once warm, whisk in the sugar until dissolved, then add the beers, liquors and spice sachet. Continue to cook on high for 2 hours, until the mixture forms what is essentially a cooked layer of egg and curd on top. Turn temperature down to warm until you're ready to serve.
To serve, whisk into fine curds, then spoon into coffee mugs. Grate fresh nutmeg on top to garnish.