Strawberry-Rhubarb Trifle with Amaretto Custard

1 1/4 cup(s) sugar

1/3 cup(s) cornstarch Salt

2 large egg yolks

1/4 cup(s) Amaretto or other almond-flavored liqueur

1 1/4 pound(s) rhubarb , trimmed and cut into 1/2-inch chunks

2 pound(s) strawberries , hulled and each cut into quarters

1/2 cup(s) heavy or whipping cream

2 (10 3/4-ounce) frozen ready-to-serve pound cakes , thawed and cut into 3/4-inch cubes