In a medium saucepan, combine the whipping cream and brown sugar. Cook over medium heat about 5 minutes until bubbles form around the edges of the pan, stirring to dissolve sugar.

In a small bowl beat the egg yolks, cinnamon, nutmeg, allspice, clove, and salt. Gradually whisk about 1/2 cup of the hot cream mixture into the egg mixture and continue to whisk until smooth. Pour the egg mixture into the cream mixture in the pan. Cook and stir over medium heat until the mixture coats a metal spoon (the mixture should be thick enough to coat the back of a spoon and leave a clear trail when a finger is drawn through it), 4 to 6 minutes. Do not boil. Strain through a fine mesh sieve into a bowl. Stir in the vanilla and the cognac, if desired. Whisk the pumpkin into the custard. Cover surface with plastic wrap to prevent a skin from forming; refrigerate until chilled, at least 3 hours or overnight.

Pour the pumpkin custard into a 1-1/2- or 2-quart ice cream maker and freeze according to the manufacturer's directions. Pack the ice cream into a freezer-safe container. Cover and freeze until firm, at least 3 hours or up to 3 days, before serving. Makes 1-1/4 quarts (ten, 1/2-cup servings).

Place 1/2 cup semisweet chocolate pieces (or 3 ounces semisweet chocolate, chopped) in a small microwave-safe bowl or ramekin. Microwave, uncovered, on 70 percent power (medium high) for 1 minute; stir. Microwave for 1-1/2 to 3 minutes more, stirring after every 15 seconds, until chocolate is melted and smooth. Spoon chocolate over mouth of cone to cover about one-third of sides. (If chocolate is too thick to spread, stir in 1 teaspoon shortening.) Place cones, top side down, on a waxed paper-lined baking sheet. Chill about 15 minutes or until set.