1. Prepare the crust by mixing graham cracker crumbs, sugar, and melted butter until combined. Press firmly into the bottom and up the sides of a 9-inch pie plate. Chill in the refrigerator.

2. In a medium saucepan, combine 2 cups of the sliced strawberries, sugar, cornstarch, and salt. Mash the strawberries slightly with a fork. Stir in the water and bring to a simmer over medium heat, stirring frequently.

3. Once simmering, cook for 2-3 minutes until the mixture has thickened and become translucent. Remove from heat.

4. Sprinkle the unflavored gelatin over the surface of the hot strawberry mixture and let it sit for 1 minute to soften. Then whisk vigorously until the gelatin is completely dissolved. Stir in the lemon juice.

5. Let the strawberry mixture cool to room temperature, stirring occasionally. Then fold in the remaining 2 cups of fresh strawberry slices.

6. Pour the strawberry filling into the prepared crust and spread evenly. Refrigerate for at least 4 hours, or until the filling is completely set.

7. Before serving, top with whipped cream and additional strawberry slices if desired.

8. Slice and serve chilled.