Line an 8×8-inch or 9×9-inch baking pan with parchment paper, leaving overhang for easy removal.

In a bowl, mix graham cracker crumbs, melted butter, and sugar until evenly combined.

Press the crust mixture firmly into the bottom of the prepared pan. Chill in the refrigerator while preparing the filling.

In a large bowl, beat the softened cream cheese until smooth and creamy.

Add powdered sugar and vanilla extract, mixing until fully incorporated.

In a separate bowl, whip the heavy cream to stiff peaks.

Gently fold the whipped cream into the cream cheese mixture until smooth and fluffy.

Spread the cheesecake filling evenly over the chilled crust.

In a small saucepan, combine strawberries, sugar, and lemon juice. Cook over medium heat until the strawberries soften and release juices.

If using cornstarch, stir it with water and add to the strawberry mixture. Cook until slightly thickened.

Remove the strawberry topping from heat and let it cool completely.

Spread the cooled strawberry topping evenly over the cheesecake layer.

Refrigerate for at least 4 hours, or overnight, until fully set.

Slice into bars and serve chilled.