In a medium bowl, beat cream with 1/4 cup sugar until stiff peaks form. In another bowl, cream together cream cheese, lemon juice, vanilla and 1/2 cup sugar. Fold 2 cups of whipped cream into cream cheese mixture. Reserve remaining whipped cream.Slice pound cake into 18 – 1/2 inch slices. Drain raspberries, reserving juice. Line the bottom of a 3 quart glass bowl or trifle bowl with one-third of the cake slices. Drizzle with some raspberry juice. Spread one-fourth of the cream cheese mixture over cake. Sift one-fourth of the cocoa over that. Sprinkle with one-third of the raspberries. Repeat layers twice. Top with remaining cream cheese mixture, whipped cream and sifted cocoa. Cover and refrigerate 4 hours before serving.