I created this recipe using key limes but you can use lime or lemons if you desire.keep in mind that there are some differences between these 3 fruits. Limes are less sweet than Key limes and lemons are more sour than all of them.
Play with the flavors to see which one you like best.
Watch the tutorial below to make sure you achieve the best cake. You will find the recipe below the video.
 

 

Ingredients:

 

*3 cups Cake Flour
* 1 Tbsp baking powder

* 3/4 tsp salt

* 2- 1/2 cups sugar

* 1 cup butter (room temperature)

* 1/2 cup vegetable shortening

* 5 large eggs

* 1 cup Buttermilk

* 6 Tbsp Key lime juice

* 2 Key limes zested (or 1 lime)

 

Directions:

Preheat oven to 350 F (lower it to 325 once you place the cake inside the oven) 

I like to bake at lower temperatures. Which require a longer period of baking. But if you

go to a higher temperature keep in mind it will take less time. 

The baking time can change too depending on the size of the pan.

 

Spray or butter and flour 2 pans. I used two 8x3 pans 

Sift flour, baking powder and salt into medium bowl. Set aside.

Using an electric mixer, cream together butter, shortening and  2 cups of the sugar.
Save the rest of the sugar for later.

Add eggs yolks one at a time, beating until well blended after each one.

Add dry ingredients in small additions to butter/sugar mixture alternately 

with the buttermilk, beginning and ending with flour mixture. Beat at low speed just until 
blended after each addition. 

Mix in lemon juice and zest. Set aside this mixture. 

In a clean dry grease free bowl, mix egg whites with a whisk attachment.

Beat until peaks are stiff but not dry and add the 1/2 cup of sugar you saved to the egg white mixture. 

Mix a bit more to make sure the sugar is mixed and the peaks stay stiff.

 

Fold the egg whites in the butter mixture. I do this in 3 steps. 

Pour batter into prepared pans. Bake cakes until tester inserted into center comes out clean, about 55 minutes. 

 

The amount of time really depends on the pans you use and your oven.

Cool cakes in pans for 10 minutes. Turn cakes out and seal them in plastic well. 

Place the cakes in the refrigerator and let them cool well. ( I leave them at least over night)

I recommend to eat the cake at room temperature.

 

Make sure you don't over mix your batter.