Prepare the strawberries for your filling. In a saucepan, combine chopped fresh strawberries, water, sugar, and cornstarch. Heat over medium heat, stirring until sugar is dissolved. Bring to a boil, reduce heat, and simmer until thick. Cool.
Mix cracker crumbs and brown sugar in a small bowl, then stir in melted butter. Press onto the bottom and 1 inch up the sides of an ungreased 9-inch springform pan. Refrigerate the crust for 30 minutes.
Beat cream cheese, sugar, lemon juice, and vanilla extract until smooth. Gradually add heavy whipping cream and beat until stiff peaks form. Fold in the reserved strawberry mixture until combined.
Transfer the cheesecake filling to the prepared crust and refrigerate, covered, overnight.
Gently toss berries with sugar and let stand 15-30 minutes to release juices. Loosen the cheesecake sides with a knife, remove the pan rim, and serve with sweetened strawberry topping and whipped cream.
Notes
For the best texture, allow the cheesecake to chill overnight in the refrigerator before serving.