Whisk together peanut butter, mascarpone, honey, vanilla extract, and a dash of salt until combined and smoothed. Transfer to a serving bowl and use the back of a spoon to create circular grooves on the top of the dip. Drizzle honey into the grooves. If serving right away, top with dry roasted peanuts and serve with fruit. If storing for later, cover with plastic wrap and stick in the fridge until ready to enjoy.