Lemon Graham Icebox Cake

I think I'm on a lemon kick, I think it's just refreshing when its hot outside..this is a yummy one..perfect for a summer party..I did not use whole milk, 2% is fine..every saved calorie helps..
P.S. I don't know why its called Icebox cake, its a mystery!

Lemon Graham Ice-Box cake

• YIELD: Serves 8
• COOK TIME:10 MINUTES
• PREP TIME:45 MINUTES
• CHILL:30 MINUTES
• COST PER SERVING:$.84
• COURSE: Cakes/Frostings, Desserts

Ingredients

• 3 large egg yolks
• 1/2 cup plus 1 tsp. sugar
• 2 tablespoons plus 1 tsp. cornstarch
• 2 teaspoons finely grated lemon zest
• 1/8 teaspoon salt
• 1 1/4 cups whole milk
• 1/2 cup lemon juice (from about 3 lemons)
• 12 graham crackers
• 1/2 cup heavy cream

Preparation

1. In a small saucepan, whisk together yolks, 1/2 cup sugar, cornstarch, lemon zest and salt. Gradually whisk in milk until smooth. Cook over medium-low heat, whisking constantly, until mixture thickens, about 5 minutes. Remove from heat and whisk in lemon juice. Strain mixture through a fine-mesh sieve into a clean bowl. Cover with plastic (pressing directly onto surface of custard to prevent a skin from forming) and refrigerate until cool, about 30 minutes.
2. Line bottom of an 8-inch baking dish with 6 graham crackers (break into pieces to fill space, if necessary). Spoon 1/2 of pudding over graham crackers, spreading into an even layer. Repeat with remaining 6 graham crackers and rest of pudding. Cover; refrigerate for at least 30 minutes, or up to overnight.
3. Just before serving, whip cream with remaining 1 tsp. sugar until it holds stiff peaks. Spread whipped cream in a thin layer over top of cake. Cut into squares and serve.