Make the Crust: Mix graham crumbs, melted butter, and sugar. Press into a springform pan or dessert cups. Chill.
Whip the Cream: Beat heavy cream to stiff peaks. Set aside.
Make the Mango Cheesecake Base: Beat cream cheese, powdered sugar, and vanilla until smooth. Add mango purée and mix again. Whisk in collagen now if using.
Fold in the Whipped Cream: Gently fold to keep the filling light and airy.
Add the Mango Layer: Mix mango purée, lemon juice, and sugar. Spoon over the filling.
Chill: Refrigerate 6–8 hours, preferably overnight.