Combine digestive or graham cracker crumbs with brown sugar and melted butter in a bowl. Press mixture firmly into the bottom of a 9-inch springform pan. Chill in the fridge.

In a small saucepan, combine fresh strawberries, sugar, and lemon juice over medium heat. Cook for 6–8 minutes until they break down. Stir in cornstarch slurry if desired and cool completely.

Beat cream cheese in a large bowl until smooth. Add sugar, mashed bananas, vanilla, and lemon juice. Mix until creamy.

Whip cold heavy cream in a separate bowl until stiff peaks form. Gently fold into the banana-cream cheese mixture.

Pour the filling over the chilled crust and smooth the top. Spoon cooled strawberry sauce over the surface and swirl with a knife if desired.

Cover the cheesecake and refrigerate for at least 6 hours, preferably overnight.

Once set, release from springform pan. Slice with a warm knife and serve chilled, optionally garnished with fresh banana slices or strawberries.