For the cupcake:
- Preheat the oven to 350°F (180°C) and put liners into a 12-cupcake pan.
- In a large bowl, mix the butter and sugar until creamy over medium-high speed. Add one egg at a time and beat after each addition. Also, incorporate vanilla and lemon zest.
- Add the flour, baking powder and salt with a strainer and alternate with the milk. Begin with the dry ingredients and finish with them.
- Scoop the cupcake batter into the muffin pan. Bake them for 15 to 18 minutes until a toothpick comes clean.
- Cool cupcakes for 5 minutes and transfer them to a rack to keep colling for 15 minutes before using them
For the Meringue:
- Beat the egg whites with cream of tartar at medium speed in a bowl of a stand mixer.
- Meanwhile, pour the water and cup of sugar into simmering in a small saucepan. Use a thermometer to check that the mixture comes to a softball. Pour the sugar mixture into the egg whites and beat them until they become a meringue and feel cold to the touch. Fill a piping bag and set it aside for further use.
For the homemade lemon curd or filling:
- Open the condensed milk can and pour it over a small bowl and add the lemon juice. Mix it well and set it aside for later.
For the dry lemons:
- Preheat the oven to 180°C and prepare a cookie sheet with parchment paper.
- Cut the lemon and even slices with a sharp knife and place them a couple of centimetres over the cookie sheet.
- Bake them for 1 hour or until they are dry. You should turn them over at half of the bake.
- Let them cool in a wire rack and store them in an airtight container in the fridge for a long time.
For the assembly of the cupcake:
- Scoop the center of the cupcakes with a little knife and reserve the top of the cupcakes. You can also use a cupcake corer if you have one. Fill them with the homemade lemon curd and top it with the top cupcake layer.
- Pipe the meringue on top and garnish with one dry lemon. If you don’t want to use the dry lemons, you can use a blow torch to broil them a little the meringue for a finished look.