Wash strawberries in cold water. Dry them with paper towels and select 2 oz. of the best-looking berries for garnish. Pass the remaining berries through a non-metallic sieve. Sift the confectioner's sugar into the strawberry purée, and fold in the whipped cream.
Soften the jelly in a little of water and dissolve it in a saucepan with the liqueur over a low flame. Let cool but not set. Gradually fold the jelly into the strawberry and cream mixture. Wrap an 8-in. soufflé mold with a collar made of cake cardboard (the collar should extend 2-in. above the edge of the dish). Pour in the strawberry and cream mixture and level off the top against the cardboard.
Freeze the semifreddo for at least an hour. Remove the cardboard and garnish the dessert with the berries, banana and pineapple before serving.
