In a medium bowl, combine graham crackers and sugar, then stir in melted butter until clumps form and mixture looks like wet sand. Press into the bottom and sides of a deep pie plate or springform pan. Chill.
To make the sauce, place berries into a blender or food processor and puree. Add sugar, boiling water, and cornstarch and blend until smooth.
Pour mixture into a saucepan over medium heat and stir constantly, until mixture comes to a boil. Once boiling, continue to stir and cook for 3 minutes until visibly thicker and jammy, then remove from heat and stir in vanilla. Let cool, placing in the refrigerator if needed.
To whip the cream, pour heavy cream into the bowl of a stand mixer (or use a bowl and hand mixer). Whip until soft peaks form, then gradually add powdered sugar and continue to whip until you have stiff peaks. Chill.
To assemble the pie, stir together sliced strawberries and cooled sauce. Then, carefully fold in the whipped cream until no streaks remain. Scoop into prepared crust, smooth top, and chill for 4 hours or until set.