Line a 9-inch square pan with parchment paper allowing the edges to extend over the pan. Pour the condensed milk and creamy peanut butter into a sauce pan over medium heat. Slowly stir the mixture for about 10 minutes until it is thin and creamy.
Remove the pan from the heat and stir in the chocolate chips until melted. Spread the fudge into the square pan using a silicone baking spatula to spread into the corners.
Refrigerate the fudge for 2-3 hours before lifting the fudge out of the pan using the parchment paper. Cut the fudge into squares. Keep refrigerated until ready to serve.