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sugar cookies

Key Lime Whoopie Pies with Macadamia Nut Buttercream

An easy key lime cake mix cookie gets spruced up into a whoopie pie with macadamia nut buttercream!
Course Dessert
Prep Time 20 minutes
Cook Time 40 minutes
Total Time 1 hour
Servings 18 sandwich cookies
Author Sarah @ The Gold Lining Girl


  • 1 key lime flavored cake mix
  • 2 eggs
  • 1/2 c. shortening
  • zest of 2 limes
  • 2 c. macadamia nuts
  • 2 tbsp. coconut oil
  • 10 tbsp. unsalted butter softened
  • 2 1/2 - 3 c. powdered sugar
  • 3-4 drops coconut extract


  • In a large mixing bowl, combine key lime cake mix, eggs, shortening, and lime zest.
  • Roll into 1-inch balls, and place on ungreased baking sheets.
  • Slightly flatten each dough ball.
  • Bake at 350 degrees for 8-10 minutes, or until edges are lightly golden.
  • Remove to a wire rack to cool completely.
  • Meanwhile, to prepare buttercream, pulse macadamia nuts and coconut oil in a food processor until smooth. You are basically creating homemade nut butter. Process it until it's as smooth as you can get it!
  • Transfer the macadamia nut butter to a large mixing bowl.
  • Add the unsalted butter, and beat to combine.
  • Add enough powdered sugar to create a frosting that is thick, but spreadable, between 2.5-3 cups.
  • Add in coconut extract.
  • Beat until light and fluffy, about 3-4 minutes.
  • Pipe or spread frosting between two cookies. Enjoy!!