I had a bit of a panic attack in the middle of our recipe. I had forgotten a key ingredient in the filling. Luckily my neighbor Theresa was able to help me out-- I can always count on her. Good neighbors are priceless.
Our recipe came from one of Jessica Seinfeld's books. I'm not all about hiding ingredients from children; I tried it when the boys were young and got caught a number of times. "What is this orange stuff under the cheese? It doesn't look like sauce...yuck! Pureed carrots???" I do put some shredded carrots and zucchini into my spaghetti sauce, but that's not really sneaky, just adding a healthy ingredient. But I was so intrigued by this Whoopie Pie recipe that uses spinach puree, I wanted to give it a try. And I'm soooooo glad I did. We used baby spinach, wilted it a bit in a pan and pureed it in the food processor (and the trusty Magic Bullet...the amount of spinach was a bit too small to finish the job in the processor).
I did swap out a couple of ingredients; instead of brown sugar, we used organic dehydrated cane juice, and coconut oil in place of the called-for "light olive oil". The filling will be better next time...when I actually remember to buy the marshmallow cream and don't have to melt marshmallows. What a sticky mess! We just added a bit more butter and vanilla to make it easier to mix. We did use dark, dutch process cocoa, because I like dark chocolate. Using regular cocoa would probably give a little different flavor.
I think I originally found the recipe on Pinterest, and it's from THIS blog.