This salty, sweet, and woody infusion is a perfect base for mixing a desert cocktail, though I wouldn’t gild the lily with too many other cocktail ingredients. Shake it up with an ounce of Bailey’s or an ounce of pumpkin spice liqueur for a decadent after dinner sweetie. Also, whatever you do, don’t throw away the boozy, caramel fat-cap you skim off the top. Melt it down and pour it over ice cream, stir it into coffee, or smear it on cinnamon toast. It’s almost better than the infusion itself.
Over medium heat, toast the walnuts for about four minutes until you can smell them, remove and set aside. In a double boiler over medium heat, add sugar and stir constantly. The sugar will melt and form clumps, eventually melting into a thick, amber-colored goo. Be careful not to burn it. Add chilled butter one tablespoon at a time, still stirring, and fully incorporating one tablespoon before adding the next. Slowly drizzle in the cream, stirring constantly. It may splatter at first, so be careful not to add it too quickly. Allow caramel to simmer for one minute. It will bubble and rise in the pot, so stir it once or twice to prevent it from boiling over or burning. Remove from heat, stir in the salt, and let cool for five minutes or so. Return to medium-low heat, and pour in the whiskey, stirring constantly until the caramel has emulsified into the liquid. Do not let the mixture boil, or the alcohol will cook out. Add walnuts to a clean one-quart Mason jar, pour in the whiskey-caramel mixture, seal, and then let sit in a cool, dark spot for 24 hours. The fat will rise to the top. Place jar in the freezer for 24 hours, then unseal it and remove the whiskey-caramel fat-cap. Reserve it for other applications. Pour infusion through a coffee filter, and then again through a fresh coffee filter.