Preheat oven to 375 degrees. Line a 9x13 baking dish with parchment paper.
Add butter, peanut butter, sugar, and vanilla to mixer and beat well until fluffy and well combined.
Beat in flour.
Press dough into prepared baking dish.
Warm jelly in microwave for 15 seconds to make it more easily spreadable. Drop spoonfuls of jelly across the dough and use a knife to press the jelly into the dough and swirl it around.
Bake for 15 minutes or until lightly golden on the edges. Cut into bars immediately. Let cool completely.
Whisk together powdered sugar and heavy cream and drizzle over cooled bars.