For the Cupcakes
- 1/ 2 cup softened butter
- 1 cup granulated sugar
- 1/ 4 cup sweetened condensed milk
- 2 eggs
- 1/ 2 cup lemon juice
- 1/ 2 teaspoon vanilla extract
- 1/ 2 cup milk
- 2 cups all-purpose flour
- 1/ 2 teaspoon salt
- 1/ 2 teaspoon baking powder
- 1/ 2 teaspoon baking soda
For the lemon curd:
- 2 1/ 2 tablespoons sweetened condensed milk
- 2 tablespoons lemon juice
- 1 tablespoon powdered sugar
For the Buttercream
- 1 cup softened butter
- 3 1/ 2 cups powdered sugar
- 2 tablespoons sweetened condensed milk
- 1 tablespoon milk
For the cupcakes:
Preheat oven to 350°F. In a large bowl with a hand mixer, or using a stand mixer, cream together butter and sugar until smooth. Mix in sweetened condensed milk to thicken, then add the eggs one at a time, mixing to incorporate.Stir in lemon juice and vanilla, and add milk once well incorporated.
Sift in all-purpose flour, salt, baking powder and baking soda. Fold into the wet mixture to create a smooth batter. Scoop into a cupcake tin which has been lined with cupcake liners.
Bake for 14-16 minutes until a toothpick inserted comes out clean. Set aside to cool.
For the Lemon Curd
Stir together all ingredients in a small bowl. Refrigerate until ready to use.
For the Buttercream
Using a hand or stand mixer, whip softened butter on low speed. Add in one cup of icing sugar and increase to medium speed once incorporated. Add in the remaining icing sugar 1/2 cup at a time until the mixture is smooth. Turn off mixer and scrape down bowl, mixing to combine.
Return mixer to medium-high speed and add in sweetened condensed milk and milk. Whip on high speed until smooth and fluffy. Transfer to a piping bag fitted with preferred tip.
For the Assembly
On a clean work surface, spread out the cooled cupcakes. Using a small corer or round piping tip, hollow out the center of each making sure to only go 3/4 of the way down. Scoop about 1 teaspoon of the chilled lemon curd into each. Pipe the buttercream on top, starting from the outside and moving up and towards the center of each cupcake. Serve immediately or refrigerate until ready to eat.