• Preheat the oven to 350°F.

Make the Cookies:

• Using an electric mixer on a medium speed, cream the butter, brown sugar and granulated sugar together for 3 minutes or until the sugar is completely mixed in.
• Whisk in the peanut butter until just combined.
• Add the egg and vanilla and whisk the mixture for another 2 minutes at a medium speed.
• Add the flour and baking powder to the bowl.
• Reduce the hand mixer to a low speed. Whisk the dry and wet ingredients together until fully combined.
• Divide the cookie dough into 12 evenly-sized balls and arrange them on a baking sheet, leaving about 2 inches between each one.
• Bake the cookies for 12 minutes.

Make the Filling:

• While they’re baking, use the hand mixer to whisk the powdered sugar and remaining peanut butter together at a medium speed until smooth and creamy.
• Remove the cookies from the oven and use a small dish or glass to create an indent in the center of each cookie.
• Transfer the cookies onto a wire cooling rack and let them cool down for 10 minutes.

Fill the Cookies:

• Transfer the peanut butter filling into a piping bag or Ziploc bag with the corner cut off.
• Pipe the filling into the center of each cookie, completely filling the indentation.
• Top the peanut butter with a spoonful of jam.