That leaves us with the first two types. The one recommended for baking oatmeal bread is old-fashioned oats. The difference between instant oats and old-fashioned oats is how they're processed.

My banana oat bread involves just mixing by hand ... leveled 1-1/2 cups of uncooked rolled oatmeal (quick or old-fashioned) 3/4 cup of buttermilk or sour milk or milk + 1 teaspoon of white vinegar or ...