Step 1

Adjust oven rack to lower-middle position and preheat to 375 degrees F. Line muffin pan with baking cup liners.

Step 2

In a small bowl, whisk flour, baking soda, baking powder and salt; set aside.

Step 3

In the bowl of a stand mixer fitted with the paddle attachment, cream butter and sugar until pale and fluffy. Reduce speed to low and mix in peanut butter. Add eggs, one at a time, beating until each is incorporated, scraping down sides of bowl as needed. Mix in vanilla. Gradually add flour mixture; beat until just combined. Mix in sour cream and peanuts.

Step 4

Divide the batter evenly among muffin pan cups. Bake, rotating tins halfway through, until golden and a cake tester inserted in centers comes out clean, about 19-22 minutes. Transfer tins to wire racks to cool completely before removing cupcakes.

Step 5

To assemble the cupcakes, place ¼ cup jam or jelly filling into a decorating bag fitted with the number 230 round decorating tip. Insert the tip into the center of the cupcake and gently squeeze the jelly into the center of the cupcake. Repeat with remaining cupcakes.

Step 6

To finish, use an offset spatula to spread frosting over each cupcake, leaving a small well in the middle. Dollop about 1 teaspoon jelly into each well. Frosted cupcakes can be refrigerated up to 1 day in airtight containers; bring to room temperature before serving.

Step 7

To make the peanut butter frosting, in the bowl of a stand mixer fitted with the paddle attachment, beat cream cheese and confectioners’ sugar until pale and fluffy. Add salt and peanut butter, and beat to combine. Beat in vanilla.

Step 8

In another bowl, with an electric mixer on medium speed, whisk cream until medium-stiff peaks form. Fold cream into peanut-butter mixture.

Step 9

Place frosting into decorating bag fitted with the 1M decorating tip and approximately 1/4″ above cupcake top at a 90° angle to cupcake surface,  pipe a spiral of icing, beginning at the outer edge and working inward, leaving a small well in the middle. Dollop about 1 teaspoon jelly into each well. Frosted cupcakes can be refrigerated up to 1 day in airtight containers; bring to room temperature before serving.