Fry bacon in a pan over medium heat until very crispy.Remove to a paper towel lined plate to drain well.
Transfer bacon to a food processor along with the 4 tsp sugar and peanuts.Grind to a medium-fine texture.Transfer to a bowl and add the peanut butter and salt to taste.Taste the mixture; you may want to add more sugar,especially if the peanut butter was unsweetened.
Cover with plastic wrap and place in fridge until very firm.
Roll the peanut butter mixture by hand or spoons into 1'' balls,placing them on a tray lined with wax paper.Chill again until firm.
Place the cocoa in a bowl;set aside.Place the chocolate chips in a heatproof bowl set over a pot of water.Heat over medium-low until the water is simmering and stir the chocolate until melted and smooth.Remove from heat.
One at a time roll the peanut butter balls in the melted chocolate and then in the cocoa powder.Serve room temperature.
Store any remaining truffles in a covered container thoroughly covered in cocoa powder for up to 1 week.