In a kettle, combine the cranberry juice, sugar, cinnamon stick and lemon juice; bring the mixture to a boil and add the pears. Heat the mixture until it just comes to a simmer and simmer the pear gently for 10-15 minutes, or until they are just tender. Remove the kettle from the heat, stir in the cranberries, and let the mixture cool. Cover and chill the mixture for at least 8 hours. The pear mixture may be made 3 days in advance and kept covered and chilled.
Make the crust:
In a food processor, blend together the flour, brown sugar, ginger, cinnamon, allspice and salt, add the butter and blend the mixture until it resembles coarse meal. In a small bowl, stir together the egg yolk and the molasses, add this to the flour mixture and pulse the motor, blending the mixture until it is combined well but still crumbly. Turn the mixture out into a 10-inch tart pan with a fluted, removable rim and press it onto the bottom and up the side of the pan. Chill the crust for 30 minutes. Prick the crust with a fork, line it with foil, and fill the foil with the rice. Bake the crust in the lower third of a preheated 375 degree oven for 15 minutes, remove the foil and rice carefully, and bake the crust for 10 minutes more. Let the crust cool in the pan on a rack.
Transfer the poached pears and half the cranberries with a slotted spoon to paper towels to drain, discard the cinnamon stick, and reserve the syrup with the remaining cranberries. In a small bowl, whisk together the eggs, sugar, sour cream, milk, vanilla, zest and a pinch of salt, stir in the drained cranberries, and spoon half of the custard into the crust. Slice the pear halves crosswise on a diagonal, arrange decoratively on the custard and spoon the remaining custard around the pears. Cont.