To temper the chocolate: Chop the chocolate in to small pieces and place in a bowl over barely simmering water to melt. Bring the chocolate up to 113 degrees F. Turn off the heat, remove the bowl from the simmering water, and let cool, stirring until it reaches 82 to 86 degrees F. It will begin to set a little around the edges at this point. Return the bowl to the hot (now turned off) water for a few seconds at a time, until it reaches 88 to 91 degrees F. Do not let it go over 91 degrees or it will go out of temper.
Pour melted milk chocolate in a candy mold with individual fluted cups to coat the insides. Pour the excess chocolate back into the bowl and let set or chill to set.
Meanwhile, mix the peanut butter with the powdered sugar. Using a small spoon or pastry bag with a large plain tip fill each chocolate cup with the peanut butter filling leaving room for a chocolate seal and chill slightly.
Using a paper cone or pastry bag filled with melted milk chocolate, fill in the surface of the cups to enclose the filling with chocolate. Let set, then turn out of the mold.
Notes about the recipe: I have two recipes for this, one where you blend the peanut butter right with the milk chocolate and then pour it into the molds which is a more direct route to the same end flavor. The other is more traditional and the one I've done here with the filling separate from the outer chocolate shell.