Peanut Butter and Banana Frosting

First off, I used this recipe to "frost chocolate cupcakes". I was unable to give this a 5 star rating without modifications. The recipe does not state the margarine is too be room temperature or softened before mixing. I assumed with most recipes that is how it should be to cream with sugar. I don't use margarine so I used butter in it's place. After seeing the amount of powdered sugar in this recipe I decided to use ALL NATURAL peanut butter. I RECOMMEND this as the frosting was still very sweet. Also, I added the mashed banana *into* the frosting. The frosting tasted delicious but was slightly runny for cupcakes, so I put in the fridge for 1 hour and it was much easier to work with. THANKFULLY, the taste of this frosting *saved* the cupcakes because they were not good at all. This was so good, I didn't even frost all the cupcakes and we ate the frosting out of the bowl! This frosting REALLY DOES taste exactly like a PB and banana sandwich! I will definitely use this recipe again. (Special thanks to *Cookies* from the Recipe Exchange for recommending this recipe to me)!