Instructions

For the cupcakes:

1. Preheat the oven to 350F and place the rack in the middle of the oven. Line 4 muffin cups and set aside.
2. Combine the buttermilk and baking soda in a small bowl and stir to mix. Gently whisk in the egg yolk and vanilla.
3. Place the flour, sugar and salt in a medium-sized mixing bowl ad whisk to blend well. Add the butter and half of the buttermilk mixture. Beat with a hand-held mixer on low speed until the dry ingredients are moistened. Increase the speed to medium and bet until the mixture is lightened and has slightly increased in volume, about 45 seconds. Scrape down the sides of the bowl. Pour in the remaining buttermilk mixture and beat on medium speed until well blended, 20 seconds. Scrape down the sides of the bowl.
4. Spoon the batter evenly into the 4 prepared cups. Fill the empty cups halfway with water to prevent them from scorching.
5. Bake the cupcakes until a tester comes out clean, about 20 to 23 minutes.
6. Remove from the oven and allow to cool in the pan for 10 minutes before removing and allowing to cool completely.

For the frosting:

1. Place the cream cheese and butter in a medium mixing bowl and beat on medium speed until blended, about 20 seconds.
2. Add the sugar, orange zest and extract, and beat to mix.
3. Add the orange juice concentrate and beat until fluffy, about 1 minute.