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

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

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