Brush flat side of amaretti with liqueur and arrange them around the side and bottom of 12-cup glass bowl (flat sides of cookies against the glass). Spread generously with red raspberry jam, being careful not to crush amaretti.
Spread 1-¼ cups custard over raspberry jam layer in bowl. Cover with single layer of cake slices. Using pastry brush, soak cake generously with ¼ to ⅓ cup Sherry. Spread thin layer of jam over cake. Top with half of drained raspberries. Carefully spoon another 1¼ cups custard over berries, repeating with remaining pound cake slices, Sherry, jam and berries. Carefully spread remaining custard over top.
Brush 8 or 9 macaroons with liqueur and arrange over custard flat side down. Place plastic wrap directly on surface of trifle. Refrigerate overnight. (Can be prepared up to 2 days ahead.)
About 3 to 4 hours before serving, whip cream in medium bowl until foamy. Add sugar and vanilla, beating until stiff but not dry. Spoon beating occasionally, swirling gently. Crush 10 to 12 macaroons. Sprinkle 1-inch border around outer edge with cream. Refrigerate until serving time.
Notes: I use a double recipe of my thick pastry cream for this, and layer the whipped cream atop the pastry cream layers rather than putting it all on top.
