In a large bowl, beat the softened cream cheese until smooth.
Add the powdered sugar, peanut butter, heavy cream, cocoa powder, and vanilla extract to the bowl. Beat until the mixture is fully combined and creamy.
Gently fold in the melted semi-sweet chocolate until just combined. Do not overmix.
Transfer the dip to a serving bowl.
Chill the dip in the refrigerator for at least 30 minutes to allow it to firm up slightly.
Top with optional chopped peanuts or chocolate chips before serving.
Notes
Serve this dip with graham crackers, apple slices, pretzels, or vanilla wafers.
For a thicker dip, reduce the heavy cream to 1/4 cup.
You can use milk chocolate instead of semi-sweet chocolate for a sweeter result.