1. In a medium bowl, cream butter until light. Then, mixed together butter and sugar until fluffy.

2. Incorporate egg yolk one at the time mixing well, then add salt (if butter is unsalted), vanilla extract and lime zest.

3. Add evaporated milk gradually while stirring with a spatula.

4. On the other hand, mix baking soda with flour, and sift flour gradually into mixture while stirring.

5. In a small bowl, blend egg white along with some lime zest and dark rum (preferably Barbancourt) until foamy.

6. Add beaten egg into mixture and stir thoroughly. Incorporate raisins thereafter.

7. Grease and dust a pan or pyrex bowl with sifted flour, then pour in mixture.

8. Preheat oven at 350 degrees, then lower it to 275 depending on the oven specifications.

9. Place bowl in the center of oven and let cook for 45-55 minutes or until golden brown. Insert a knife into cake to ensure it comes out clean.

10. Remove bowl from oven and let cool 10 minutes!