Lemon Cupcakes with Lemon Curd

We've been on a testing hunt for the ideal cupcake. I've tried a few and they were fine but I must admit, this one from Ina Garten's "Barefoot Contessa Parties" is remarkable. If you're looking for her recipe in the book, it's really her Lemon Cake recipe with Lemon Glaze. I just altered things a little to make them work. I also noticed, or rather Psychgrad pointed it out to me, that Anne from Cooking with Anne had a gorgeous looking curd filled cupcake on her blog. Hmmm...the wheels started moving. Anne really became the inspiration for the flavour and the filling.

Ingredients

1/2 pound unsalted butter (room temperature)
2 cups granulated sugar
4 extra-large eggs (room temperature)
1/3 cup grated lemon zest (6-8 lemons)(Note: I used 5 large lemons)
3 cups all-purpose flour
1/2 tsp baking powder
1/2 tsp baking soda
1 tsp kosher salt
1/4 cup lemon juice
3/4 cup buttermilk at room temperature
1 tsp pure vanilla extract

Method
1. Preheat the oven to 350 degrees. Line muffin cups (I used jumbo size)
2. Cream the butter and sugar in the bowl of an electric mixer fitted with the paddle attachment for about 5 minutes (scraping sides frequently).
3. With the mixer on medium speed, add the eggs, one at a time, and the lemon zest
4. Sift together the flour, baking powder, baking soda and salt in a bowl. Add the flour and buttermilk mixtures alternately to the butter, beginning and ending with the flour.
5. Divide the batter evenly to muffin cups (my yeild was 27)
I used Dorie Greenspan's "Baking From My Home To Yours" recipe for the lemon curd.


Lemon Curd

1 1/4 cups sugar
3/4 stick (6 tablespoons) unsalted butter, cut into 6 pieces
1 large egg
6 large egg yolks
Freshly squeezed juice of 4 lemons

Method

1. Put all the ingredients in a medium heavy-bottomed saucepan and stir with a heatproof spatula to moisten the sugar.
2. Put the pan over medium-low heat and cook, stirring without stopping until the butter melts and the mixture thickens like custard, 4-6 minutes. (Keep your eyes on the pan because the curd can curdle quickly. It is cooked enough when you can run your finger along the spatula and the curd doesn't run into the track you've created)
Don't worry if the curd looks thin at this point - it will thicken more as it cools.
3. Remove the pan from the heat and scrape the curd into a heatproof jar or a bowl. (I sieved it through a strainer first and was glad I did).
4. Press a piece of plastic wrap against the curd to create an airtight seal and cool to room temperature before storing in the refrigerator.