To poach the pears, in a medium saucepan, combine the water, honey, seeds scraped from 1 vanilla bean and vanilla bean. Bring to a boil and cook, stirring, until the honey dissolves. Add the pear halves, reduce the heat, cover and simmer until the pears are tender when pierced with a sharp knife, about 12 minutes. Transfer the pears with a slotted spoon to a cutting board and let cool slightly. Cut into thin slices.

To make the creme anglaise, in a small saucepan, bring 2 cups cream to a bare boil with the remaining vanilla bean and scraped seeds over medium heat. Remove from the heat and let cool slightly. In a medium bowl, beat the egg yolks and sugar until ribbons form. Gradually add 1 cup of the warm cream, and mix well. Add back to the pot with the remaining cream and stirring constantly cook over medium heat until thick enough to coat the back of a spoon. Remove from the heat and strain through a fine mesh strainer, discarding the vanilla bean. Press a piece of plastic wrap against the surface to prevent a skin from forming. Let cool slightly.

In a medium bowl, whip the remaining 2 cups cream with the sugar.

To assemble the trifle, cut the cake into 1/2-inch thick slices to fit tightly into the bottom of a trifle bowl (or a 1 1/2-quart decorative glass bowl), and slightly up the sides about 1-inch.

Drizzle the cake with Port. In a mixing bowl toss the berries with 2 tablespoons Port, stirring to bruise the berries slightly. Layer 1/3 of the pears over the top of the cake, then top with 1/3 of the creme anglaise, followed by 1/3 of the raspberries. Repeat the process, layering the remaining ingredients, finishing with the whipped cream on top. Decorate with chocolate shavings.