Instructions

1. Put about a third of the truffle slices into a small bowl, add cognac, madeira, port, and sherry, cover with plastic wrap, and set aside to let marinate overnight. Put remaining truffle slices and eggs (in their shells) together in a tightly covered bowl and refrigerate overnight.
2. Remove truffle slices from bowl, cut all but 4 into ⅛'' dice, and set aside. Put marinated truffle slices and any truffle trimmings in center of a 4''-square piece of cheesecloth, reserving marinade. Gather corners of cheesecloth together, tie closed with kitchen twine, and set aside.
3. Combine double cream, whipping cream, and reserved truffle marinade in a medium-heavy saucepan. Add truffle sachet and bring just to a boil over medium heat. Remove saucepan from heat and set aside.
4. Meanwhile, crack eggs and separate yolks from whites, putting yolks into a medium mixing bowl and reserving whites for another use. Add sugar to yolks and whisk until yolks become pale yellow and sugar has dissolved. Slowly pour half of the hot cream into yolks, whisking constantly, then gradually add mixture back into hot cream in saucepan, stirring with a wooden spoon. Reduce heat to medium-low. Cook, stirring constantly, until bubbles begin to appear, about 4 minutes. Immediately strain through a fine sieve into a bowl. Discard truffle sachet. Stir reserved diced truffles into custard.
5. Put 4 raspberries into each of four 4-oz. heatproof dishes. Fill dishes with custard. Let cool, cover with plastic, and refrigerate until set, at least 4 hours. Before serving, sprinkle 1 tsp. demerara sugar evenly over each custard and use a blowtorch to caramelize tops. Put 1 of the reserved truffle slices on each custard.