Simple Yellow Cupcakes with Tangerine Curd

I made another batch of my favorite yellow cupcakes a few weeks ago, this time paired with tangerine curd.  I'm just crazy about these cupcakes - they always bake up perfectly and look gorgeous, plus they're moist and delicious!  I made the tangerine curd because we had a couple of tangerines that looked like they were going downhill, and I wanted to use them up.  It's a really easy recipe that makes a small amount of curd - perfect for using up some extra tangerines and "frosting" a batch of cupcakes!  I love the flavor of orange-y curds like this one - sweet and tangy with great tangerine flavor. 

Simple Yellow Cupcakes 

Tangerine Curd (adapted from The Kitchn, original recipe here)

1/2 cup freshly squeezed tangerine juice
Zest of two tangerines (finely grated with a microplane zester)
1 T lemon juice
1 large egg
2 large yolks
1/4 cup granulated sugar
4 tablespoons unsalted butter, cut into chunks and softened
Pinch of salt

1. Pour the tangerine juice into a small sauce pan over medium-high heat. Bring the juice to a rapid simmer and let it reduce down to approximately 1/4 cup. This should take 2-4 minutes.
2. Transfer the tangerine juice to a measuring cup to cool. Stir in the zest and lemon juice.
3. In a small saucepan, whisk together the egg, yolks, and sugar. When the orange juice is no longer hot, whisk it into the egg mixture in a steady stream.  Set the saucepan over medium heat. Whisk constantly until the mixture has thickened to a pudding-like consistency - about 6-8 minutes or until the mixture is 180°. 
4. Strain the mixture into a clean bowl to remove the zest and any bits of cooked egg.  Briskly whisk in the butter and the pinch of salt while the curd is still hot.
5. Cover the curd with plastic wrap touching the surface so that it does not form a skin as it cools.  Chill until ready to use, up to one week.