Preheat oven to 350 degrees. Lightly coat a Bundt pan with the cooking spray and set aside.
In a medium bowl, combine cake flour with sugar, salt, and baking powder. Sift well.
In a large mixing bowl, combine mayonnaise, oil, milk, and lemon juice. Stir until smooth.
Gently fold half the flour mixture into the liquid mixture. Continue mixing in flour, a little at a time, until all the flour is added and the batter is smooth.
In a stainless steel or glass bowl, combine egg whites and cream of tartar, and beat on high speed with electric mixer, gradually adding sugar, until stiff peaks form.
Gently fold meringue into the cake batter a small amount at a time. Pour batter in prepared pan.
Bake for 50 minuts or until cake tests done. Remove from oven and cool for 15 minutes before removing from pan.
In a small bowl, combine confetioners' sugar and lemon juice, and stir until sugar dissolves. Drizzle glaze over the cake. Garnish with fresh lemon slices if desired.