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Key Lime Pie Cake

My classic vanilla cake layers, filled with a fluffy lime curd and graham cracker crust crumbs, all held together with a light lime buttercream frosting. A light and tangy cake!
Print Recipe
Prep Time 20 mins
Cook Time 45 mins
Course Dessert
Cuisine American
Servings 16 people

Ingredients
  

For the vanilla cake layers

  • 3 ¼ cups flour
  • 3 cups sugar
  • 2½ tsp baking powder
  • 1 tsp salt
  • 1 cup salted butter 2 sticks, room temp
  • 1 cup egg whites room temp, about 7 eggs worth
  • 1½ cups buttermilk room temp
  • ⅛ cup vegetable oil
  • 2 tsp vanilla

For the Key Lime Curd Filling

  • ¾ cup sugar
  • 4 tsp lime zest
  • ½ cup key lime juice
  • pinch salt
  • 3 large eggs
  • 3 large egg yolks
  • 4 tbsp butter cold
  • 1 tsp vanilla
  • ½ cup heavy whipping cream
  • 1 tbsp sugar
  • 1 tsp vanilla

For the graham cracker crust crumbs

  • 1 pack honeymaid graham crackers
  • 2 tbsp sugar
  • ½ cube butter melted
  • 1 tsp vanilla
  • ¼ tsp salt

For the lime buttercream

  • 2 cups salted butter room temp
  • 8-9 cups powder sugar
  • 1 tsp salt
  • 3-4 tbsp heavy cream
  • 2 tbsp lime juice
  • 2 tsp vanilla

Instructions
 

For the vanilla cake layers

  • Preheat oven to 350° and spray and line with parchment rounds 3, 8'' cake pans. Set aside.
  • In the bowl of a stand mixer fitted ith the paddle attachment, combine all dry ingredients.
  • Cut the butter into the flour mixture. Mix on low speed until no large chunks of butter are seen. Mix should be like a crumbly sand.
  • Add the egg whites and mix until just combined. Don't over mix.
  • Add half of the buttermilk, mix for a few seconds and then add the rest. Add in the oil and vanilla and mix until barely combined.
  • Now turn the mixer onto high and mix for 20 sewconds. Batter should be lighter in color, and fluffy!
  • Add 2 cups of batter into each pan. Bake for 15-20 minutes or until toothpick conmes out clean! Let cakes sit in pan for about 10 minutes before turning onto a cooling wire wrack. Let cool completely before frosting. It's best if your cakes are chilled in the freezer!

For the Key Lime Curd Filling

  • To prepare...
    In a separate bowl, combine and whisk the 3 eggs and 3 egg yolks. Cut your butter into small cubes. Have your vanilla handy.
  • In a medium sized sauce pan, over medium heat, mix the sugar, lime zest, lime juice, and salt together.
  • Whisk in the egg mixture. Keep stirring for about 10 minutes. Until its thick almost like pudding. Turn off the heat. Add butter and vanilla. Stir until butter has melted. If adding food dye, add it now!
  • Through a thin wire strainer, strain mixture. This should take out most of the now cooked zest. pressing plastic wrap directly onto the mixture, cover the bowl. This prevents a film forming on the top.
  • Once curd is COMPLETELY chilled. Make your whipped cream. Add heavy cream to a stand mixer with the whisk attachment. Beat on high, adding the sugar and vanilla as its going. Once stiff peaks appear, stop the mixer. You dont want to over mix or else you will make butter.
  • Fold whipped cream into the curd until no streaks are left. Chill until ready for use.

For the graham cracker crumbs

  • In a food processor, or in a gallon sized ziplock bag, crush the crackers until its sand like.
    Mix in melted butter, sugar, vanilla, and salt. Place on a cookie sheet lined with tin foil. Bake for 10-15 minutes, stirring every 5 minutes. Let cool.

For the lime buttercream

  • Mix the butter on high until lighter in color and creamy. One cup at a time, add in the powder sugar, aletrnating with small splashes of heavy cream.
  • Once all powder sugar is mixed in, add salt, lime juice, and vanilla. If it seems too dry, add more cream, if it seems too wet, add more powder sugar.
Keyword buttercream, cake, citrus, lime, vanilla