In a small bowl, whisk together jam and water, set aside.
Cut the pound cake into thin slices about 1/8-inch thick. Take one of the wine glasses that you will use to serve the dessert in and cut out a circle from each slice of cake by pressing the rim of the glass into the cake. When you're done, wash the glass.
In a large mixing bowl, whip the heavy cream with a whisk or electric mixer until it just begins to hold soft peaks when you pull the beaters out. Sprinkle in the sugar and continue beating to soft peaks.
Drop a couple of large spoonfuls of the cream into 2 wine glasses then press in a cake round followed by a thin layer of raspberry sauce. Repeat until you've almost filled the glass. End with a layer of cake, then cream and then drizzled berry sauce over the top.