In a small saucepan over medium heat, melt butter and whisk in the brown sugar and peanut butter. Heat until sugar dissolves (about one minute). Remove from heat immediately and allow to cool to room temperature.

In a large mixing bowl, beat cream cheese with powdered sugar until creamy (about 3-4 minutes). On low speed, add in the cooled brown sugar mixture. Mix until combined.

Fold in mini chocolate chips and chopped Reese's cups. Serve immediately or refrigerate until ready. Enjoy with pretzels, animal crackers, or graham sticks.