pecans vs walnuts and molasses vs honey
I can't always get pecans here in South America. I've found when I make our traditional Christmas pecan pie that walnuts work just as well. In fact, we almost prefer them because they're a little less sweet than pecans. Using walnuts doesn't change the flavor of the pie.
Molasses is also sometimes hard to get (as is corn syrup). I use honey instead of molasses and sometimes flavor it with a teaspoon of maple flavoring or vanilla. It's much healthier than corn syrup too!