Cupcake: Preheat oven to 180 degrees C. Line 2 x 12 hole muffin tins with paper patty pans.
Place everything except for the cupcake centres into a medium sized bowl. Using an electric mixer, beat until well combined. Divide the batter evenly between the 24 patty pans.
Cook in the preheated oven for approximately 18 minutes or until centre bounces back to touch and a skewer comes out clean.
Cool slightly then fill will the salted caramel filling,
following instructions on the packet.
Icing: Beat the butter and peanut butter until creamy then add half the icing sugar, beating well. Add the rest of the icing sugar and the 3 tablespoons milk. Add the rest of the milk if icing is too thick.
To Assemble: Ensure the cupcakes are cooled completely then pipe or spoon over cakes and sprinkle with nuts.