i would use name brand marshmallows because i have found that it has a better quality and taste. There are many other recipes, but this is an easier recipe than most others. Any questions comment below and i will respond back to you.
Grease the inside of the glass bowl with the vegetable shortening (i prefer Crisco)
put the marshmallows into the greased bowl with the flavorings and water. then stir around so the marshmallows get covered
place the glass bowl with its contents into the microwave and start microwave just until the mixture starts to melt
stir the product until it is nice and smooth
add all the powdered sugar into the bowl of marshmallow goop and mix for four minutes ( you can also use a stand mixer or hand mixer on a low speed) until it is well mixed
color fondant now with any color you would like. Wrap in cling wrap and let sit in the fridge for 10 minutes to rest
take it out and let come back to room temperature until ready to use ( use in three days or less)(leave in fridge until ready to use)