Candied Cranberries (Prepare Overnight): Combine water and 1½ cups sugar in a saucepan over medium heat; stir until dissolved. Remove from heat, cool slightly, add cranberries, cover, refrigerate overnight.
Drain cranberries; toss in ½ cup sugar to coat; set aside.
Quick Cranberry Jam: Combine cranberries, sugar, and vanilla extract in a saucepan over medium heat; cook, stirring frequently, 12-15 minutes; cool.
Preheat oven to 325°F; grease 9-inch springform pan; wrap pan with foil.
Crust: Mix graham crumbs, brown sugar, melted butter, vanilla extract; press into pan bottom and sides halfway.
Spread half of cranberry jam over crust.
Cheesecake Filling: Beat cream cheese and sugar until smooth; add vanilla and sour cream.
Add eggs one at a time, beating well after each; scrape bowl.
Add cornstarch; pour in heavy cream; mix smooth.
Split vanilla bean, scrape seeds; stir into batter.
Pour batter over jam layer.
Place springform pan in water-filled roasting pan halfway up sides; bake 70-75 mins.
Turn off oven; open door halfway; rest cheesecake in oven 10 mins.
Remove foil; let cheesecake rest 20 mins.
Run greased knife around edges; cool 1 hour.
Spread remaining cranberry jam on top; wrap; refrigerate at least 4 hours.
White Chocolate Mousse: Melt white chocolate.
Beat cream cheese till smooth; gradually add melted chocolate.
Fold in whipped topping thoroughly.
Spread mousse evenly over cheesecake.
Add candied cranberries on top before serving if desired.