I like the Ultimate Sweetener (from birch bark) as a sugar substitute because you can use it in equal substitution for any amount sugar (its the same sweetness, moisture content, & granulation) without altering the recipe. (tacanow.org)
I subbed quick cooking oats for 1/2 of the flour (equal substitution) and used a bit more banana and pumpkin to add a bit of extra moisture. (skinnytaste.com)
unfortunately, it's not an equal substitution. (laurafuentes.com)