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, add in cooled brown sugar mixture and mix until combined.

Fold in mini chocolate chips and chopped Reese's cups. Serve immediately or store in refrigerator until ready to serve. Enjoy with pretzels, animal crackers, or fruit.