1 pound cake or equal amounts of genoise or sponge cake
2-4 tablespoons marsala, rum or brandy
1 cup strawberry jam
2 cups fresh raspberries
1 1/2 cups heavy cream
1 tablespoon sugar
For the custard:
Mix together sugar and cornstarch in a large saucepan. Add egg yolks and whisk to combine; then gradually whisk in milk. Cook over medium-low heat, stirring constantly, until custards thickens to the consistency of thick cream, about 10 minutes. Transfer to a large bowl and add vanilla. Cover surface of custard with plastic wrap to prevent a skin forming, and refrigerate until completely chilled, about 2 hours.
For the trifle:
Cut cake into 2-inch by 1-inch pieces. Arrange a layer of cake in the bottom of a large trifle glass bowl. Sprinkle cake with some of the Marsala; then spread a layer of strawberry jam over the cake; then scatter some of the raspberries over the jam. Pour some of the custard over the berries. Repeat layering, ending with custard. Cover with plastic wrap, and refrigerate for at least 3 hours. Remove trifle from refrigerator about 1 hour before serving. Just before serving, put heavy cream and sugar in a large bowl. Beat cream until it holds soft peaks. Do not over beat. Decorate trifle with large dollops of whipped cream.