Preheat oven to 350° F.
Sift together flour and powdered sugar. Set aside.
Combine egg whites and lime juice in a large bowl. Beat until soft peaks form.
Stir together granulated sugar and lime zest. Add by the tablespoon to egg whites and continue to beat, adding until all sugar is gone, until stiff peaks form.
Fold flour and powdered sugar into stiff-beaten egg whites in four small additions.
Turn out into an ungreased 10-inch tube pan.
Bake for 40 - 45 minutes or until top springs back when touched lightly.
Turn pan over and cool with cake still inside pan. Cool completely.
Remove from pan gently and serve with Raspberry Sauce.
Raspberry Sauce: Microwave preserves for 30 seconds until warm. This may take more or less time depending on your microwave.
Stir well until smooth.
Add lime juice and stir until well combined.