Line a cookie sheet with parchment paper and spray well with cooking spray.
Unwrap caramels and put in a microwave bowl. Add butter and cream, and microwave for 30 second increments, stirring between each. Repeat until smooth - but use the shortest time possible to melt the caramel.
Add the mixed nuts (and about a teaspoon of salt if you have unsalted nuts like I did) and combine well.
Allow to rest for at least 15 minutes, mixing occasionally. The caramel will run away from the nuts if you skip this step - the mixture needs to be fairly firm before you portion it.
Scoop or spoon onto baking sheet uniformly. Refrigerate until firm, at least 30 minutes.
Melt white chocolate in microwave for 15 second increments, stirring well until smooth. Do not overheat.
Dip caramel cluster into white chocolate using a fork and turn to coat completely. Allow excess chocolate to drip back into bowl, and place candy back on baking sheet.
If the candy gets too pliable while you are coating with chocolate, return to refrigerator or freezer for a few minutes to firm up.
Refrigerate candy until set, 30 - 60 minutes.