Place egg whites in a large bowl; let stand at room temperature for 30 minutes. Sift flour and ¾ cup plus 2 tablespoons sugar together twice; set aside.
Add cream of tartar, extracts and salt to egg whites; beat on medium speed until soft peaks form. Gradually add remaining sugar, 2 tablespoons at a time, beating on high until stiff peaks form. Gradually fold in flour mixture, a fourth at a time.
Gently spoon into an ungreased 10-in. tube pan. Cut through batter with a knife to remove air pockets. Bake on the lowest oven rack at 375° for 30-35 minutes or until top springs back when lightly touched and cracks feel dry. Immediately invert pan; cool completely, about 1 hour.
Lemon Cream Sauce:
Whisk eggs and sugar in a heavy saucepan over low heat. Stir in the lemon juice, butter and lemon zest. Cook until mixture thickens and reaches 160°, about 15 minutes. Transfer to a bowl; refrigerate until chilled.
Assembly:
Run a knife around sides and center tube of pan. Remove cake to a serving plate. Fold whipped cream into lemon sauce. Add to cake and enjoy! Refrigerate any leftover sauce.