Using a long, serrated knife, level the top of one of the cake layers, cutting off just enough so that none of the brown crust remains. Flip over the layer and again cut off any brown crust on the bottom. This will become the middle layer. Level the tops of the two other layers, cutting off just enough so that they are the same height as the middle layer.
In a small bowl, stir the jam with a whisk to break up any large lumps. Using a rubber spatula, fold the jam into the whipped cream.
Place one of the cake layers that has been leveled on only one side cut side up on a 10-inch cake cardboard or serving platter. Brush it with Soaking Solution.
Using a metal icing spatula, spread 1 heaping cup of the whipped cream on the cake; the icing should be about 3/8 inch thick. Place the middle layer over the whipped cream. Brush it with Soaking Solution. Spread it with another cup of the whipped cream. Place the remaining layer cut side down on the whipped cream. Brush the top with Soaking solution. Ice the cake with a final coat of whipped cream. The top should be perfectly level and form a right angle with the sides.
Fill a pastry bag fitted with a #1 or #2 star tip with the remaining whipped cream, and pipe an "S" border around both the top edge and the base of the cake.
This cake is best served the day it is made, but it may be stored overnight in an airtight cake container in the refrigerator. Makes one 9-inch, three-layer cake.