Ingredients
1¼cupsall-purpose flour,spoon and leveled
½tspbaking soda
¼tspsalt
½cupcanola oil,or vegetable oil
½cupcreamy peanut butter
1cuplight brown sugar,or dark brown sugar, packed
1large egg,at room temperature
⅓cupsour cream,at room temperature
1½tsppure vanilla extract
¾cupwhole milk,at room temperature
⅓cuppeanuts,very finely crushed, or chopped
1cupunsalted butter,softened to room temperature
3½cupsconfectioners’ sugar
½cupunsweetened natural cocoa powder,or dutch-process cocoa powder
3tbspheavy cream,or milk
⅓cupcreamy peanut butter
1tsppure vanilla extract
¼tspsalt
Mini Reese’s Peanut Butter Cups,or chopped peanuts, optional, to garnish
Preparation
Preheat the oven to 350 degrees F.
Line a 12-cup muffin pan with cupcake liners. Line a second pan with 2 to 3 liners.
Whisk the flour, baking soda, and salt together in a medium bowl. Set aside.
Using a handheld mixer, stand mixer fitted with a whisk or paddle attachment, or a whisk, mix the oil, peanut butter, brown sugar, egg, sour cream, and vanilla extract together in a large bowl.
Add the dry ingredients, milk, and peanuts and whisk or beat together until completely combined.
Avoid overmixing. The batter will be slightly thick.
Pour or spoon the batter into the liners, filling only ⅔ full to avoid baking over the sides.
Bake for 21 to 23 minutes, or until a toothpick inserted in the center comes out clean and the tops of the cupcakes spring back when gently touched.
Allow the cupcakes to cool completely before frosting.
With a handheld or stand mixer fitted with a paddle or whisk attachment, beat the butter on medium speed until creamy, about 2 minutes.
Add the confectioners’ sugar, cocoa powder, and milk.
Beat on low speed for 30 seconds, then add the peanut butter, vanilla extract, and salt.
Beat on medium-high speed for 2 minutes until combined.
Add ¼ cup more confectioners’ sugar if frosting is too thin, or another 1 to 2 tablespoons of cream or milk if frosting is too thick.
Taste. Add extra peanut butter or a pinch of salt, if desired.
Frost the cooled cupcakes.
Garnish with a peanut butter cup, if desired.
Cover and store leftovers in the refrigerator for up to 5 days.
