Would this work?

[Ricekrispie22]

Can I substitute the shortbread base in a Millionaire's shortbread recipe for a soft/chewy cookie base made with Betty Crockers choc chip cookie mix?
And can I just use carnation caramel instead of boiling condensed milk and sugar? Would it be too runny?

No idea about the caramel I'm afraid. I suspect that technically you could substitute the base but it would possibly be a little overwhelming - 2 layers of choc plus the caramel. The shortbread is a plain background to the other flavours. Only way to see if it works is to try it, but don't tell people it's millionaire' s shortbread as it won't be!

It would taste nice I'm sure, but personally one of the things I like about millionaires shortbread is the contrast between gooey caramel and crisp shortbread.

Thanks, I'll stick to shortbread.

I think the carnation caramel would be too runny, it would ooze out.