Preheat oven to 350°F (175°C).
Line a 9x9 inch baking pan with parchment paper.
Mix graham cracker crumbs, melted butter, and sugar.
Press firmly into the bottom of the pan.
Bake crust for 8–10 minutes. Let cool.
Beat cream cheese and sugar until smooth.
Add eggs one at a time.
Mix in vanilla and sour cream.
Pour filling over cooled crust.
Mix strawberry puree with sugar and cornstarch.
Spoon over cheesecake batter and swirl gently.
Bake for 30–35 minutes until center is set.
Cool completely, then chill for at least 2 hours.
Cut into bars and decorate with heart shapes.