To prepare crust, mix graham cracker crumbs, melted butter and cocoa powder in a small bowl, and mix until a moist yet crumbly mixture forms. Firmly press the mixture into the bottom and sides of the pie dish. Bake for 10 minutes. Let cool completely on a wire rack.
To prepare filling, in the bowl of a standing mixer fitted with the whisk attachment, beat the cream until it holds firm peaks. Remove cream from bowl and keep cold in fridge. In the same bowl, use a paddle attachment, beat cream cheese until it’s soft and creamy. Add sugar, vanilla and melted chocolate, continue beating until combined. Gently fold 1/3 of the whipped cream into the cream cheese mixture to lighten the mixture, then add the remaining cream and continue folding until incorporated.
Pour the cream mixture in the cooled crust. Smooth the top with a spatula. Arrange strawberries on top of the pie. Refrigerate the pie until set, about 3 hours, or preferably overnight.
Sprinkle powdered sugar on top of the pie before serving.