Ok for this recipe kettle caramelization is not needed. Too many caramel malts in this recipe make it overpowering and unbalanced
If you still want to do it however, simply go with your base malt and do 3% roasted barley.
Collect a gallon of wort prior to your boil, and boil the hell out of it in another vessel. Boil down to 2-3 pints and return to main kettle.
Desert Sky Brewing Co.
Sierra Vista, AZ