Set a pot with an inch of water on the stove over high heat. Bring the water up to a boil, then reduce the heat to medium-low.
Set another pot on top of it.
Add in the chocolate chips and shortening.
Stir occasionally until melted.
Line a 12-cup mini muffin pan with liners.
Put a spoonful of the melted chocolate in each cup.
When done, put the muffin pan in the fridge for about a half an hour.
In the meantime prepare the peanut butter mixture.
Again, set a pot with an inch of water on the stove over high heat. Bring the water up to a boil, then reduce the heat to medium-low.
Set another pot on top of it and pour in the peanut butter, margarine, powdered sugar, and vanilla extract.
Cook over medium heat, stirring occasionally, until melted, about 5 minutes.
Take the muffin pan out of the fridge and begin by putting a small lump of peanut butter filling in the chocolate cup, but dont spread it. You want to leave the sides empty so that the chocolate which goes on top will cover up the entire cookie.
But, before you cover them with the rest of the melted chocolate, put them back in the fridge for another 15 minutes so that the peanut butter can set just a bit.
Pour the rest of the melted chocolate on top of each cup and put them back in the fridge for another half an hour.