Stir the chopped strawberries and granulated white sugar in a medium-sized mixing bowl and then set to the side for at least 5 minutes.
While the strawberries are marinating in the sugar, beat the whipping cream and vanilla extract in a large mixing bowl with a hand or stand mixer.
While whipping the cream, gradually add the powdered sugar and pudding mix and continue beating until stiff peaks form for about 3 minutes.
Beat in the mascarpone cheese, one package at a time, until smooth and creamy, 2-3 minutes.
Mash the strawberries and sugar together in the bowl and then stir in the strawberry pie filling until combined.
Assemble the Tiramisu by dipping ladyfingers in the strawberry mixture to coat and then placing them in a deep, 9x9 inch square pan in a single layer.
Spread ½ of the strawberry mixture on top of the lady finger layer.
Scoop out ½ of the whipped cream mixture and dollop it along the outside edges of the pan. Spread it with an offset spatula or knife into an even layer, about ½ inch thick.
Repeat step 6, creating another layer of strawberry-coated ladyfingers and then spreading on the rest of the strawberry mixture.
Finish by dolloping on the remaining whipped cream mixture and spreading it into an even layer on top.
Cover well with plastic wrap and refrigerate for at least 6 hours or overnight.
When ready to serve, top with sliced strawberries, optional, cut into squares, and serve.