This one is the best I have made so far..
Tastes best when its one to two days old.
(Adapted from lifeloveandsugar.com)
3/4 cup (168g) salted butter, room temp
1 cup (235g) sugar (I used little less)
2 egg whites
1.5 tsp vanilla extract
1.5 cups (390g) all purpose flour
1/8 tsp baking soda
1 plus 1/3 tsp baking powder
3/4 cup (180ml) milk
1. Preheat the oven to 350 degrees. Grease the pan and Line a 8-inch cake pan with parchment paper in the bottom.
2. Beat the butter and sugar in a large bowl on medium speed about 2 minutes, until light and fluffy. Scrape down the sides of the bowl.
3. Add the egg whites and vanilla and beat on medium speed for another 1 minute, no more. The texture of the batter will change and become thicker and may seem a little curdled.
4. Combine the flour, baking soda and baking powder in a medium sized bowl.
5. Add about one-third of the flour mixture to the batter and beat on medium speed until incorporated.
6. Add about half of the milk and beat on medium speed until incorporated.
7. Continue adding dry and wet ingredients, scraping down the sides of the bowl as needed, and beating until incorporated after each addition.
8. Pour the batter into the cake pan and spread evenly.
9. Bake for 35-40 minutes, or until a toothpick inserted into the middle of the cakes comes out clean.
10. Remove the cake from oven and allow to cool for 3-5 minutes.
11. Now remove it from pan and place it on the cooling rack and let it cool down completely.