Chocolate Cupcakes with Peanut Butter Frosting

I got this recipe from Ina Garden.
It is heavenly.
Originally it had coffee in it but I took it out for those of us that don't do coffee.
A must try.

1 1/2 sticks unsalted butter, at room temperature

2/3 cup granulated sugar

2/3 cup light brown sugar, packed

2 extra-large eggs, at room temperature

2 teaspoons pure vanilla extract

1 cup buttermilk, shaken, at room temperature

1/2 cup sour cream, at room temperature

1 3/4 cups all-purpose flour

1 cup cocoa powder

1 1/2 teaspoons baking soda

1/2 teaspoon salt

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Preheat the oven to 350ºF.

Line cupcake pans with paper liners.
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In a lrg. bowl, cream the butter and 2 sugars on high speed until light and fluffy, approximately 5 minutes.

Lower the speed to medium, add the eggs 1 at a time, then add the vanilla and mix well.

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In a separate small bowl, whisk together the buttermilk and sour cream.

In another med. bowl, sift together the flour, cocoa, baking soda, and salt.

On low speed, add the buttermilk mixture and the flour mixture alternately in thirds, to the large bowl with the butter and sugar mixture, beginning with the buttermilk mixture and ending with the flour mixture.

Mix only until blended.
Divide the batter among the cupcake pans.

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Bake in the middle of the oven for 20 to 25 minutes, until a toothpick comes out clean.

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Cool for 10 minutes, remove from the pans, and allow to cool completely before frosting.

{Makes about 15 cupcakes.}
Frost each cupcake with Peanut Butter Icing.
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{Peanut Butter Icing}
1 cup powdered sugar

1 cup creamy peanut butter

5 tablespoons unsalted butter, at room temperature

3/4 teaspoon pure vanilla extract

1/4 teaspoon salt

1/3 cup heavy cream

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Place the confectioners’ sugar, peanut butter, butter, vanilla, and salt in a med. bowl.

Mix on medium-low speed until creamy, scraping down the bowl with a rubber spatula as you work.

Add the cream and beat on high speed until the mixture is light and smooth.