Mix water, sugars, and molasses in saucepan. Bring to boil.
Boil on medium heat for about 2 minutes.
Add peanut butter and marshmallow cream and mix well, until smooth and creamy.
Serve on bread or buns. Or anything else you like peanut butter with.
You can use any kind of molasses or Karo for this recipe. It just depends on how well you like that robust molasses flavor. Blackstrap molasses has a very strong and distinct flavor that some people do not like. I would personally recommend using light-tasting molasses. And if you're not a molasses person, feel free to use light Karo. If you just want to try the recipe and don't want to make a lot, go ahead and halve the recipe.