You can sub the prune puree with 2 tablespoons real butter. Alternately, you can use 1 tablespoon butter and 1 tablespoon Greek Yogurt or avocado.
You can use your choice of sugar alternative, like sucanat.
You can use whole wheat flour or gluten-free flour.
Chocolate chips can be used in place of the cocoa nibs. Be sure your choice of cocoa nibs or chips are 70% cocoa or higher.