In a saucepan, combine 2 cups of diced strawberries, granulated sugar, cornstarch, lemon juice, and water. Cook over medium heat until the mixture reaches a gentle boil, then reduce to a simmer for about 15 minutes until thickened. After cooking, mash the strawberries for a smoother texture, allow the mixture to cool, and stir in the remaining diced strawberries for a fresh burst.

Grease a 9-inch pie dish with a touch of butter to prevent sticking. In a food processor, blend the graham crackers and brown sugar until fine crumbs form. Next, pour in the melted unsalted butter and pulse until the mixture resembles wet sand. Press the crumb mixture firmly into the bottom and up the sides of the pie dish, then freeze the crust for 15 minutes to set.

Using an electric mixer, whip the heavy cream in a separate bowl until stiff peaks form, then set aside. In another bowl, combine cream cheese, powdered sugar, sour cream, and vanilla extract, blending until the mixture is smooth and creamy. Gently fold the whipped cream into the cream cheese mixture, ensuring it remains light and airy.

Spread the cream cheese filling evenly over the chilled graham cracker crust, smoothing the top with a spatula for an even layer. Carefully spoon the strawberry topping over the cream cheese filling, allowing it to cascade downwards for an appealing look. Cover the pie with plastic wrap and refrigerate for at least 6 hours to let the flavors meld together, although overnight chilling is preferred for best results.

When ready to serve your delightful No Bake Strawberry Cream Cheese Pie, you can layer additional whipped cream on top for a decadent finish. Slice the pie into wedges and enjoy it chilled, garnished with fresh strawberry slices or a sprig of mint if desired.