* For the bread cubes, just use as much bread as it takes to fill the bottom of your dish generously, plus up about 1 to 1.5 inches. If you've added too much to soak up the liquid, just remove some. And if it looks too wet, add some more bread.
* I HIGHLY recommend using pumpkin butter
as it has a concentrated pumpkin flavor and is much sweeter than puree. But if using puree instead of butter, it's important to compensate the flavor by adding a bit more puree, pumpkin pie spice, and a little agave nectar, brown sugar or maple syrup to the batter. Otherwise, it will lack that delicious fall, pumpkin flavor you're going for.
* I used 2%, but use skim or low-fat for a lighter recipe. Alternatively, use non-dairy such as soy or almond.