Slice cake into 1/4 inch slices. Trim and discard crust. Line bottom of deep glass bowl with 1/3 of the cake slices. Sprinkle with 1/4 cup sherry. Arrange strawberry halves, cut side out around lower edge of bowl. Spoon 2 cups of the pudding over cake slices.
Place remaining cake slices over pudding. Gently spread strawberry preserves over cake. Top with remaining cake. Pour remaining 1/2 cup sherry over cake. Spoon remaining pudding over cake. Chill 3 or 4 hours. Spread whipped topping over trifle. Garnish with strawberries and mint leaves. Yield 14 to 16 servings.
