Preheat oven.
Make crust: Mix graham cracker crumbs, sugar, salt, and melted butter.
Bake crust at 350°F (175°C) for 10 minutes.
Beat cream cheese until smooth using electric mixer.
Add powdered sugar and eggs; mix until combined.
Blend in sour cream and vanilla extract.
Add cornstarch and beat until just combined.
Spread filling evenly over baked crust.
Bake at 325°F (160°C) for 30 minutes until set.
Cool completely, then chill for at least 4 hours.
Cook mango topping in saucepan until thickened.
Spread mango topping over chilled cheesecake.
Cut into bars. Garnish with mint, zest, and extra mango if desired.