In a medium saucepan cook and stir beaten eggs, half-and-half, and the 1/4 cup sugar over medium heat until it just coats a metal spoon. Remove pan from heat. Stir in 1 teaspoon vanilla. Place saucepan into a sink of ice water for 1 to 2 minutes, stirring constantly, to cool quickly. Pour custard into a bowl; cover surface with plastic wrap. Chill at least 1 hour.
In a large skillet, bring wine, water, the 1/2 cup sugar, and star anise to boiling. Add pears; return to boiling. Reduce heat, cover, and simmer 10 to 15 minutes or until pears are tender. Remove pears from skillet with a slotted spoon.
Bring liquid in skillet to boiling; cook, uncovered, about 8 minutes or until reduced to 1-1/3 cups. Remove star anise. Reserve 1/3 cup of the pear liquid.
Place pear halves on a cutting board, flat side down. Make seven lengthwise cuts in each, starting 1/2-inch from stem end and cutting to the bottom. Stir liqueur, brandy, or 1 teaspoon vanilla into 1/3 cup of the pear liquid; set aside.
Split ladyfingers; layer one third in a 2-quart trifle dish or straight-sided glass serving bowl. Sprinkle with one third of the pear liquid. Dot with one third of the preserves. Spread one third of the custard over the top. Arrange two of the pear halves atop custard. Sprinkle with one third of the raspberries. Repeat layers two more times, using three pear halves per layer. Cover and chill for 3 to 4 hours.
To serve, beat whipping cream, 1 tablespoon sugar, and 1/2 teaspoon vanilla in a chilled mixing bowl with an electric mixer on medium speed until soft peaks form (tips curl). Pipe whipped cream atop trifle using a pastry bag fitted with a large star tip. Garnish with additional poached pears, if desired.