1. For the cake:

2. 1. Preheat the oven to 350°F. Grease and flour a cake pan.

3. 2. In a bowl, mix together the flour, sugar, and baking powder.

4. 3. Beat the egg whites until stiff peaks form, then gently fold them into the flour mixture.

5. 4. Add the lime juice, lime zest, and vanilla extract to the batter and mix well.

6. 5. Pour the batter into the prepared cake pan and smooth the top.

7. 6. Bake the cake for about 30-35 minutes, until it's golden brown and a toothpick comes out clean.

8. 7. Remove the cake from the oven and let it cool completely.

9.

10. For the frosting:

11. 1. Mix together the light sour cream and the juice of half a lime.

12. 2. Frost the cooled cake with the sour cream frosting.

13.

14. Serve and enjoy the lime cake!