Arrange pears in an oven-proof pan with a tight-fitting lid; add red wine, 1/2 cup brown sugar, vanilla bean and seeds, and the peel and juice of 1 orange. Bring pear mixture to a boil; sprinkle with half the walnuts.
Bake the pear mixture in the preheated oven until pears are tender, 20 to 30 minutes, basting pears with red wine syrup every 10 minutes. Remove from oven and cool; remove the vanilla bean and orange peel from the red wine syrup.
Arrange the remaining walnuts on a baking sheet and bake in the preheated oven until toasted and fragrant, 5 minutes.
Place the toasted walnuts in a food processor and pour in the red wine syrup; pulse until paste-like consistency. Transfer to a bowl. Whisk cream, sour cream, zest and juice of 1 orange, and 2 teaspoons brown sugar into walnut-red wine paste until smooth.