1boxButter golden cake mix*baked into 24 cupcakes according to package directions
For The Filling:
1tspfresh lime zest
1/2cupkey lime juice
14ozcan sweetened condensed milk
For The Frosting:
16tbspbutter (2 sticks)softened
5cupsconfectioners sugarsifted
2tbspvanilla extract
3tbspkey lime juice
1tspfresh lime zest
3tbsp half and half
Instructions
Make boxed cake mix per package directions and bake into 24 cupcakes.
While cupcakes are cooling, first make the filling.
Whisk together 1/2 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.
Notes
For extra key lime flavor in the cupcakes, you can add 1-2 tbsp key lime juice in place of some of the water used for the cupcake batter.