Pound Cake: Cut into thin slices (1cm) thick and spread with strawberry / raspberry jam and dice into cubes.
Mascarpone Cream: Place the heavy whipping cream, mascarpone, sugar, and vanilla extract in a large bowl. Whip until soft peaks form. (Do not over whip as cream and mascarpone will tend to split).
To Assemble the Trifles: Nicely place the diced pound cake in the bottom of each trifle glass. Sprinkle each slice of pound cake with about 1 teaspoon Grand Marnier (optional). Next spoon about 1-2 tablespoons of Strawberry Sauce on top of the diced pound cake. Cover the sauce with nicely arranged assorted berries. Place a large dollop of the whipped cream/mascarpone mixture on top of the berries. Repeat the layers, starting with the pound cake. Cover and refrigerate for 5 to 24 hours to allow the flavors to mingle.
Just before serving sprinkle each trifle with roasted coarsely chopped assorted nuts.