Mix graham cracker crumbs, sugar, and melted butter until well-blended. Press mixture evenly into an 8 or 9 inch pie plate.
Bake at 375℉ for 7 minutes. Set aside and let cool.
Pour heavy cream into the bowl of a stand mixer fitted with the whisk attachment. Beat on medium speed until stiff peaks form.
In another bowl, combine cream cheese, powdered sugar, and vanilla extract in the stand mixer bowl. Beat for about 2 minutes.
Fold in whipped cream and sour cream with the cream cheese mixture and mix until completely mixed together.
Spread cream filling into the cooled pie crust. Place in the fridge.
In a small saucepan, combine sugar and cornstarch; stir in water and 1 ½ cups raspberries.
Bring to a boil; cook and stir for 2 minutes or until thickened. Transfer to a bowl; refrigerate until chilled.
Once raspberry topping is cooled down (make sure it's completely cooled), spread topping over cream cheese filling. Garnish with remaining berries (fresh berries work best as garnish, but frozen will be fine too.
Serve immediately or chill until serving.
Notes
If I use frozen raspberries to make this, I usually don't thaw them first - I just use them frozen.You can make this pie one day ahead of eating it.