Lemon Curd Cupcakes with Lemon Buttercream

This morning, as I was loading up my basket with lemons, I mentioned to our greengrocer that I was going to make some lemon curd. I asked him if he had ever tried it, and he had never heard of it. I tried to recall the first time I ate lemon curd, but it's a flavour that my taste buds have been familiar with since childhood, so I could't quite remember just how long ago I discovered just how delicious it is. My Grandad used to make the best lemon curd around, and I wonder if my first taste of the beautiful citrus curd was from a batch made by his very talented hands.

I have come to love filling my cupcakes with things - like salted caramel, jam, chocolate ganache, raspberry cream, and now, lemon curd. I definitely get more enjoyment out of eating a little cake with something slightly gooey in the middle, rather than having just a big old hunk of cake topped with icing. Although these cupcakes would be perfectly good without lemon curd in the middle, it definitely makes them that bit more wonderful, in my humble opinion.

If you would like to make these with lemon curd, I would recommend using this recipe, and halving the quantity. This will give you plenty of lemon curd for the cake batter, filling the centres of the cakes and adding some to the icing, and you'll have a little leftover to spread on toast.

ingredients (makes approx. 18 cupcakes, or 2 x 8" round sponge cakes)
225g unsalted butter at room temperature*
225g caster sugar
225g self raising flour
4 free range eggs
2 tsp baking powder
1 tsp vanilla extract
zest of 1-2 lemons, depending on personal preference
1 heaped dessertspoon of lemon curd

1) Pre-heat the oven to 180C / gas mark 4 and line cupcake trays with cases
2) In a large mixing bowl, cream the butter and sugar until well combined and fluffy.
3) Beat in the eggs, one at a time, scraping down the sides of the bowl to ensure all mixture is incorporated.**
4) Sieve in the flour and baking powder, and mix until all of the flour is incorporated.
5) Stir in the zest and lemon curd
6) Divide the batter between the cupcake cases (or tins, if you're making a large sponge cake instead). I tend to put a rounded dessertspoon of mixture, plus a little extra.
7) Bake in the preheated oven for 15-20 minutes, or until a skewer inserted into the middle of the cake comes out clean.
8) Remove from the cupcake tray as soon as possible, and leave to cool on a wire rack.
9) If you're filling the cakes with some lemon curd, use a cupcake corer or a knife to cut out the centre of the cake, then spoon lemon curd into the hole until it's level with the top of the cupcake.

for the buttercream
500g icing (confectioner's) sugar
160g unsalted butter
50ml milk
lemon curd
lemon zest (optional - I didn't use this, as I dislike the texture of zest in a smooth frosting. However, if you'd like the buttercream to be very lemony, the zest would achieve this flavour.)

method for the buttercream
1) Beat together the icing sugar and butter until the crumbly mixture starts to come together. (If you're using a freestanding mixer, I would recommend covering the bowl with a tea towel to stop icing sugar flying everywhere.)
2) Slowly add the milk a little at a time, beating until you have a smooth buttercream.
3) I'm afraid I didn't measure out the lemon curd, so I can't tell you precisely how much to use, but it was approximately 2 dessertspoons worth. I would encourage you to add just a little at a time, as the curd softens the consistency of the buttercream, and if you're planning on piping it onto the cakes, you want to avoid it become too runny.
4) Spread or pipe the buttercream onto the cooled cupcakes.

Baking Notes
* Butter temperature:
During the Winter months, I tend to find that when my butter is at room temperature, it is a little bit hard. There are a couple of options as to how you can solve this problem:
1) Beat the butter first before adding the sugar to warm it up and soften it.
2) Pop it in the microwave on a low power for a few seconds. I don't have a microwave, so I can't tell you how many seconds, I would just recommend you watch it like a hawk, as you don't want it to melt.

** Eggs
The temperature of eggs is important in baking. Ideally, you want to bake with them when they are at room temperature, otherwise your batter is very likely to curdle. If this happens, just add a little of the flour to the mixture as you add the eggs.