To assemble the strawberry shortcake, place one cake layer, flat side down on a small cake stand or a serving plate. Use a fork or a wooden skewer to poke holes in the cake, before carefully topping with 3/4 cup of the strawberry filling. Spoon the filling over the entire layer and make sure the juices go into the cake layer (they should start seeping into the holes you poked) and not the plate.
Top the strawberries with 1 cup of the whipped cream, using a rubber spatula to make sure the cream stays in the middle of the cake — when you place the second cake layer on the cream, the cream will automatically spread out over the berries from the pressure of the second cake layer.
Top the cream with a second cake layer. Repeat the first two steps for this layer, before topping with the third and final cake layer. Make sure that the final cake layer has the flat side up of the cake up.
Cover the final layer with the last of the whipped cream and garnish with whole berries. For best flavor, eat immediately OR allow the cake to refrigerate for about an hour before slicing. Allowing it to refrigerate for an hour allows the cake to soak up some of the strawberries' juices.