7/10 Whoopie Pies With Salted Buttercream Filling

Background - My daughter, Dharma, suggested I make Whoopie Pies. Whoopie pies are like two cupcake tops with frosting in-between them. Some people call them Moon Pies. I wanted to make something a little different so I chose this recipe that includes salted buttercream filling, rather than the standard vanilla. Things did NOT go as planned. I'll get to that...

http://www.foodess.com/2009/02/whoopie-pies-with-salted-caramel-buttercream/

Here are the ingredients for the cookies:

Here are the ingredients for the buttercream:

1. Whisk flour, baking soda (not pictured, oops), cocoa, and salt in a bowl.

2. In a stand mixer, cream butter and sugars.

3. Add other wet ingredients, then flour mixture a little at a time until fully incorporated.

4. Drop spoonfuls onto baking sheet. I used my silicone mat!!!!!!!!!!!!!!!!!!

5. Bake for 10-12 minutes. Set on a cooling rack and make more! I ended up reducing the size of the cookies because I wanted to make more for Marcus to take to work. You'll see at the end...

6. While the cookies cool, make the buttercream. Mix water and sugar in a saucepan and bring to a boil. Swirl gently to mix and let it bubble until it becomes a golden color.

7. Remove from heat, add cream, and stir. You now have caramel. Move the caramel to a glass bowl quickly, because you will probably have to microwave it when you add it to the frosting mix.

8. Put egg whites, sugar, and salt in a bowl over a pot of simmering water. Whisk until a candy thermometer reads 140 degrees. Transfer to the stand mixer and whisk until firm peaks appear.

9. Add butter a little bit at a time, then add vanilla and caramel. Heat the caramel in the microwave for 10 seconds at a time until it's able to pour out of the glass bowl. I only had to heat it for 10 seconds total.

This is where everything fell apart. See how thin this "filling" is? These are the exact measurements the recipe calls for, but there's no way this can be used as a frosting-like filling between the two cookies. This calls for drastic action! 

I added a crapload of powdered sugar, a few scoops at a time, until I ran out!!!! Probably 1 cup in all. Still not thick enough...

Having run out of my only conceivable frosting thickener, I turned to the internet for help. Somewhere I found a Q&A post about this very problem, and someone suggested adding cornstarch. I started adding a spoonful at a time and mixing. I probably added 1/4 to 1/3 of a cup cornstarch. It worked...

Finally, I was able to add the filling to the flat side of a cookie, and sandwich it between another same-size cookie. Though I lost the "salted buttercream" flavor through the addition of all the extra powdered sugar, at least the consistency was right. 

The two large whoopie pies on the plate are for me and Marcus. The rest are for his work. Thank you for the challenge Dharma!!!!!!!!!!!!!!!!!

If you like this recipe, please let me know. Also, if you like any of my tips and tricks, please tell me!