Rinse and drain fresh berries. (Thaw frozen berries according to package directions.) Set a large, sturdy sieve over a bowl and put raspberries in sieve. Using back of a spoon, force raspberries through holes in sieve, removing all stems and seeds as you go. (You should end up with 2/3 cup to 1 cup raspberry puree.) Stir in sugar and lemon juice.
Using large holes of a grater, make small chocolate shavings. If you prefer larger curls, use a vegetable peeler.
Place slices of pound cake on individual serving plates and top each with a scoop of ice cream. Pour a small amount of raspberry sauce over ice cream and sprinkle chocolate shavings all around. Serve with remaining sauce.