Lemon Curd Mousse Cake

Name: Lemon Curd Mousse Cake
Ingredients: 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; Nonstick vegetable oil spray; 2 cups shortbread cookie crumbs (about 7 1/2 ounces); 1 /4 cup (1/2 stick) unsalted butter, melted; 5 tablespoons water; 4 teaspoons unflavored gelatin; 6 large egg whites; 3 /4 cup sugar; 1 1/2 cups chilled heavy whipping cream; Lemon slices, cut into quarters (garnish)