Can I make this caramel the "usual" way instead of using golden syrup and condensed milk I've been following this millionaire's shortbread recipe to make as a Christmas gift. 

In the second stage, the caramel recipe uses condensed milk and golden syrup instead of sugar and cream.


  For the topping
  150g/5oz butter
  1 x 379g can condensed milk
  100g/3½oz golden syrup 
  
  For the topping, heat the butter, condensed milk and golden syrup in a
  saucepan, stirring occasionally until the butter is melted and the
  mixture is smooth.
  
  Increase the heat and bring the mixture to the boil, stirring
  frequently. The caramel will thicken and turn golden-brown. Set aside
  to cool slightly, then pour over the cooled shortbread. Allow to cool
  completely.


I've looked around at other recipes and it seems like the majority of them use this method. I suspect it's because this is more error-proof and beginner friendly. Using a sugar syrup that is already liquid means that it's not going to be as prone to crystallise, and it probably won't need to be cooked as long (or monitored as closely as usual candy making).

I'm quite comfortable making caramel the "usual" way with butter/sugar/cream. I usually make a "wet" caramel with water. I'd like to know if I can make it this way instead. My concerns are as follows:  


Not getting the temperature/consistency correct (I'm not 100% sure which stage to aim for. Soft ball I think?)  
Crystallising. I'm thinking about adding in glucose syrup as a stabiliser but I'd be concerned about crystallisation in any case.  
Perhaps there's a reason why golden syrup/condensed milk are used here that I don't know about.


So in summary, how do I go about switching out this stage of the recipe for a more traditional method? Is there an advantage to following the recipe as is, or is it safe for me to switch out as a confident caramel maker?
With millionaire's shortbread you need a caramel with the right consistency, it needs to be soft enough to cut through (and chew) but have enough resistance not to squish out. The golden syrup, condensed milk and butter recipe comes out with just the right consistency, is extremely reliable and easy to make which is why it is popular. 

There's no reason you can't make your own caramel, you just have to make sure you don't get the end result too soft or hard.