In saucepan, combine cornstarch with 2 tsp. cold water until smooth. Stir in cherries, reserved liquid, sugar and cinnamon. Over medium-high heat bring to a boil; cook, stirring constantly, until thickened, about 1 minute. Transfer to bowl and refrigerate at least 30 minutes.

Cream Cheese Fillings
2 pkgs. (8 oz.) each cream cheese, at room temperature
3/4 cup sugar, divided
1 tsp. vanilla
1 container (16 oz.) + 1-1/2 cups Cool Whip, thawed, divided
1/2 cup cocoa powder
1 pkg. prepared chocolate crumb pie crust
Fresh cherries, optional
Grated chocolate, optional

In mixer bowl, beat 8 oz. cream cheese with 1/4 cup sugar and vanilla until combined and fluffy, about 2 minutes. At low speed, gradually beat in 3 cups Cool Whip until combined and smooth. Spread mixture in crust; refrigerate. In same bowl beat remaining cream cheese with remaining sugar until combined and fluffy. Sift cocoa over mixture; at medium speed beat until combined and smooth. Reduce speed to low; gradually beat in 3 cups Cool Whip until smooth.

Spread cherry filling over cream cheese filling in crust leaving 1" border around edge of pie. Spread chocolate mixture over so that it seals to crust. Spread with remaining Cool Whip. Refrigerate until ready to serve. Garnish with fresh cherries and grated chocolate, if desired.