Beat cheese, sugar, and 1/2 cup whipping cream at medium speed with an electric mixer until creamy.
Beat remaining 2 cups whipping cream with an electric mixer until soft peaks form. Fold into cheese mixture.
Stir together 1 cup hot water and coffee granules until dissolved. Stir in liqueur.
Split ladyfingers in half, and brush cut sides of ladyfingers evenly with coffee mixture.
Arrange one-fourth of ladyfingers in bottom of a 4-quart trifle bowl. Top with one-fourth of cheese mixture. Repeat layers 3 times. Sprinkle with cocoa. Chill tiramisu at least 2 hours.
* Cream cheese may be substituted for mascarpone cheese.