Preheat oven to 175°C (350°F).
Mix graham cracker crumbs, melted butter, and brown sugar.
Press mixture into a lined baking dish.
Bake crust for 10 minutes and let cool slightly.
In a saucepan, cook strawberries, rhubarb, sugar, and cornstarch for 5 minutes until softened.
Beat cream cheese and sugar until smooth.
Add eggs one at a time, then mix in vanilla and sour cream.
Pour cheesecake filling over crust.
Spoon fruit mixture over the cheesecake layer and swirl gently.
Bake for 35–40 minutes until center is set.
Cool completely, then refrigerate for at least 3 hours before slicing.