This recipe is one of my all-time favourites, right from my childhood home.
In a large mixing bowl or the bowl of an electric mixer, cream together the butter and peanut butter. Add the icing sugar and rice crispies, and stir until well combined. Roll into 1-inch balls, and set aside.
Melt the chocolate in 30 second bursts in the microwave, stirring between each, until melted and smooth.
Coat peanut butter balls with chocolate, using a fork to dip them in, a spoon to cover them, and a knife to scrape off the excess.
Set the peanut butter balls in fridge or freezer until the chocolate is set (4-10 minutes), or leave them to set at cool room temperature.
Trim the excess chocolate with a sharp knife, and store the peanut butter balls in sealed containers.