Preheat your oven to 350°F (175°C) and line a muffin tin with cupcake liners.

In a mixing bowl, cream together the softened butter and sugar until light and fluffy.

Add the eggs and vanilla extract, mixing well until combined.

In another bowl, whisk together the flour, baking powder, and salt.

Gradually add this dry mixture to the wet ingredients, alternating with the milk, and mix until just combined.

Spoon the cupcake batter into the prepared muffin tin, filling each liner about two-thirds full.

Bake in the preheated oven for 18-20 minutes, or until a toothpick comes out clean. Let them cool completely.

In a saucepan, whisk together the lemon juice, sugar, egg yolks, and lemon zest.

Cook on medium heat, stirring constantly until the mixture thickens and coats the back of a spoon (about 10 minutes).

Once thick, remove from heat and stir in the butter until melted and smooth. Allow it to cool.

In a clean bowl, beat the egg whites and cream of tartar until soft peaks form.

Gradually add the sugar, one tablespoon at a time, until the meringue reaches stiff peaks and is glossy.

Mix in the vanilla extract.

Once the cupcakes are cool, use a small knife to cut a circle in the center of each one, creating a well.

Fill each well generously with the cooled lemon curd, then top with a generous dollop of meringue.

Using a kitchen torch, gently toast the meringue until golden. If you don't have a torch, place the cupcakes under the broiler for a minute or two, but watch closely to prevent burning.