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+ servings
close up of a cupcakes with lime zest on top

Key Lime Cupcakes

These Key Lime Cupcakes are a light buttery cupcake with key lime filling topped with a rich and delicious key lime buttercream frosting.  
Course Dessert
Cuisine American
Prep Time 20 minutes
Cook Time 20 minutes
Total Time 40 minutes
Servings 24
Calories 263kcal
Author Amee


  • 1 box Butter golden cake mix *baked into 24 cupcakes according to package directions
  • For The Filling:
  • 1 teaspoon fresh lime zest
  • ½ cup key lime juice
  • 14 oz can sweetened condensed milk
  • For The Frosting:
  • 16 tablespoon butter (2 sticks) softened
  • 5 cups confectioners sugar sifted
  • 2 tablespoon vanilla extract
  • 3 tablespoon key lime juice
  • 1 teaspoon fresh lime zest
  • 3 tbsp half and half


  • Make boxed cake mix per package directions and bake into 24 cupcakes.
  • While cupcakes are cooling, first make the filling.
  • Whisk together ½ cup key lime juice and the sweetened condensed milk.
  • Place filling mixture inside a piping bag with a Wilton #230 filling tip attached. While holding a cupcake in one hand, use the other hand to insert the cupcake filling tip in the middle of the cupcake. Slowly pull the tip up and out as you feel the cupcake start to expand. Repeat with remaining cupcakes.
  • Next, make the frosting.
  • In a mixing bowl, cream softened butter and 1 cup powdered sugar until blended. Add lime zest, vanilla, lime juice and half and half. Slowly add remaining sugar, one cup at a time, until frosting is creamy and smooth.
  • Pipe frosting onto cupcakes and garnish with any remaining lime zest, if desired.
  • Store cupcakes in a sealed container in the refrigerator and set out to come to room temperature before serving.


For extra key lime flavor in the cupcakes, you can add 1-2 tablespoon key lime juice in place of some of the water used for the cupcake batter.


Calories: 263kcal | Carbohydrates: 53g | Protein: 2g | Fat: 16g | Fiber: 1g | Iron: 1mg