Curd:

• 2 1/3 cups sugar
• 4 teaspoons cornstarch
• 1 cup fresh lemon juice
• 4 large eggs
• 4 large egg yolks
• 3/4 cup (1 1/2 sticks) unsalted butter, cut into 1/2-inch cubes

Crust:

• Nonstick vegetable oil spray
• 2 cups shortbread cookie crumbs (about 7 1/2 ounces)
• 1/4 cup (1/2 stick) unsalted butter, melted

Mousse:

• 5 tablespoons water
• 4 teaspoons unflavored gelatin
• 6 large egg whites
• 3/4 cup sugar
• 1 1/2 cups chilled heavy whipping cream

Garnish:

• Lemon slices, cut into quarters

For curd:

Mix sugar and cornstarch in heavy medium sized saucepan. Gradually add lemon juice, whisking until all cornstarch dissolves. Whisk in eggs and yolks. Add butter.

Stir over medium heat until curd thickens and boils, about 12 to 15 minutes. You’ll want to make this on the thick side – make sure it coats the back of the spoon well and leaves a very distinct line.

Transfer to medium bowl, press plastic wrap onto the surface of the curd and chill until cold. The chilling time will vary, usually four to six hours. May be made a week ahead.

For crust:

Preheat oven to 350°F. Spray bottom of 8 or 9 inch diameter spring form pan with nonstick spray.

Blend cookie crumbs and butter in small bowl. Press onto bottom of pan. Bake until golden, about 15 minutes. Cool.

Note: Cookies can easily be made into crumbs by placing in a large ziploc bag and crushing with a rolling pin.

For mousse:

Pour 5 tablespoons water into small saucepan. Sprinkle gelatin evenly over, If necessary, gently press down on the gelatin to submerge. Let stand until gelatin softens, about 15 minutes.

Meanwhile, stir  3/4 cup curd in another small saucepan over medium-low heat until very warm.

Place an additional 1 3/4 cups lemon curd in large bowl.

As soon as the gelatin has softened, stir over low heat until dissolved and liquid is clear (do not boil).

Whisk warm gelatin mixture into the 3/4 cup warm curd. Gradually whisk gelatin-curd mixture into the 1 3/4 cups of curd in large bowl.

Using electric mixer, beat egg whites in medium bowl until soft peaks form. Gradually add sugar, beating until whites are thick and glossy. Fold whites into curd mixture in 3 additions.

Using same beaters and bowl, beat cream until stiff peaks form. Fold into egg white-curd mixture in 3 additions.

Spoon enough mousse over cooled crust to fill pan completely, but make sure to save at least a cup and a half into small bowl and reserve. Cover and chill mousse cake, reserved mousse, and remaining curd overnight.

Note: if there is a concern about the raw egg whites, use pasteurized eggs or heat the whites and the sugar over a double boiler, whisking constantly until temperature reaches 160 degrees. immediately remove from heat.

To serve:

Using long thin knife, cut around cake to loosen. Remove pan sides. Gently spread 3/4 cup of remaining curd over cake. (I prefer to refrigerate the cake at this point and take the reserved mousse out to warm up to room temperature or close to it, about an hour.)

Transfer reserved mousse to pastry bag fitted with a star tip. Pipe rosettes of mousse around top edge of cake. Chill cake until ready to serve. (Can be made up to 8 hours ahead.)

Note: I have a set of notes on a printable pdf on the blog post that will really help in making this a success.

from the kitchen of http://www.frugalhausfrau.com, adapted from Bon Appetit