I have another baking conundrum, now that my family birthday cake recipe was sorted out, and my bread recipe dilemma was solved: How to get the chocolate on my toffee bars to stick to the cookie base. I use the recipe in the Silver Palate cookbook with only two changes: I swap some of the brown sugar in the cookie base for maple sugar (a happy accident that turned out to be terrific) and I use a good quality chocolate, not chocolate chips, for the top layer. Last night, I was especially meticulous. The chocolate was evenly chopped and distributed over the cookie base when it was still hot, it was thoroughly melted and spread very, very carefully with an off-set spatula, all the way to the corners of the pans. The bars were completely cooled over night on the counter before they were cut and were never refrigerated. But, every time I don't use grocery-store brand chocolate chips, the chocolate layer separates from the cookie layer when the bars are cut. All I can think of is better grade chocolate has less 'sticking power', but that's only a guess. Thoughts most welcome!