Line a 9x9 square baking pan with parchment paper or aluminum foil and set aside.
In a microwave safe bowl, combine the peanut butter and honey. Microwave for about one minute or until runny and easy to whisk together. Add in the vanilla and whisk to combine.
Using a spoon or spatula, mix in the flour and salt, adding a little more flour if needed. Press the mixture into the prepared pan and set in the fridge while you melt the chocolate.
To melt the chocolate, place the chocolate chips in a microwave safe bowl and heat on high in 15 second intervals just until melted. Pour the melted chocolate on top of the peanut butter base and spread into an even layer. Scatter the top with chopped peanuts, if using, and place the pan back in the fridge for 20 to 30 minutes to set.
To cut the squares, use a knife that has been run under hot water.