Ingredients
1 20-ounce loaf challah or brioche, cut into 3/4-inch cubes; makes 12 cups (may substitute brioche)
3 Bosc pears, 2 1/2 of them peeled and cut into 3/4-inch chunks; makes 3 cups (1/2 pear wrapped thightly in plastic wrap to prevent oxidation, reserved for garnish)
12 ounces white chocolate, cut into 1/2-inch chunks
1 1/2 cups heavy cream (1/2 cup reserved for garnish)
1/2 vanilla bean, split with seeds scraped
9 extra-large eggs, at room temperature
1 scant cup (granulated) sugar
2 tablespoons pear-flavored liqueur, such as Poire William (optional)
1 tablespoon confectioners' sugar, for garnish and for sprinkling (optional)