Preheat oven to 400°F. Unroll refrigerated pie crust (or use homemade pie crust) and place in a 9-inch pie plate. Cover with parchment paper and pie weights or dried beans to prevent bubbling. Bake for 12-15 minutes, until lightly browned.

While the crust bakes, prepare the filling. In a medium saucepan, whisk together sugar, cornstarch, and water. Cook over medium-low heat, whisking constantly, until boiling and thickened (about 2 minutes).

Remove from heat and whisk in the strawberry gelatin powder until dissolved. Let cool slightly, or refrigerate for about 20 minutes to thicken.

Remove the baked crust from the oven and discard the parchment and weights. Let the crust cool completely.

Arrange the sliced strawberries in the cooled pie crust. Pour or spoon the thickened gelatin mixture over the strawberries.

Refrigerate the pie for at least 5 hours, or preferably overnight, until the filling is set.

Slice and serve, topped with whipped cream if desired.