I don't have that book oli, but it does give you the recipe for the carmel for the bavarain, correct? If so I would assume you'd be using the same carmel from the bavarian (either the recipe for the bavarian includes this extra amount of carmel or make the recipe x2 so you have enough for your glaze also).
It sounded strange at first to use a heavy carmel on a cake when you asked about purchased carmels. From what you posted it's mostly an apricot glaze with carmel in it. It's probably not going to thicken it much with those proportions but it will add a little more interest to the purchased apricot. You'd just heat (or not) the two together and cool before appling that as a glaze to your cake.
P.S. That's alot of glaze for one cake, what's that about?
Try it if you want to learn the orginal recipe. Personally it's not appealing to me, I'd go with a different frosting or brown sugar glaze that's not going to be as sticky and thin.
__________________
"Bakers are born, not made. We are exacting people who delight in submitting ourselves to rules and formulas if it means achieving repeatable perfection", Rose Levy Beranbaum |