I've tried a few different caramel muds, but none of them really taste very caramelly. They're just sweet cakes with a hint of brown sugar. 

I confess, being in the US, I am not familiar with mud cakes.  I hear of them all the time from my Brit friends, but I don't know what makes a cake a "mud" cake.  Sorry.

I did a search of mud cakes to see how they differ from any other cake.  According to what I read, I believe the *Original* WASC recipe would be a good basis for a caramel mud cake.  I also found this highly rated recipe:

https://www.taste.com.au/recipes/caramel-mud-cake/ba48c9c7-9821-44e0-a336-8ce0e1488b9f

Hi, I’m from Australia so I’m very familiar with mud cake! ( eaten many too!

oh yeah -- the golden syrup thing --  i don't think we get that product here exactly as england and australia do -- we have a substitute though but it might not be just right kwim -- one little thing can through off a recipe and you still can get a great cake but it's not like y'all's -- i've never tried to make one for that reason --

in the meantime here's some "mudcake for breakfast" -- wonder if there's a recipe, it'd prolly be americanized idk -- not widely read ~

https://www.amazon.com/Cake-Breakfast-Carolina-Arbors-Murder-ebook/dp/B07NKP684T/ref=sr_1_1?dchild=1&keywords=mud-cake-for-breakfast&qid=1602782120&sr=8-1

NINE authors and they only spit out 216 pages? wow

Oh my goodness, I’m so sorry! I posted a longer reply but it didn’t post, it seems to be playing up on me! 

I understand what you  it mean than the caramel mud recipes don’t taste like the rich decadent ones that you can buy. But someone told me that the secret is butterscotch schnapps! I don’t know how to do a link but if you go to queen.com.au you will find the recipe there. I haven’t tried this one but it looks good!