What is the filling in whoopie pies made of?

Traditional fillings for whoopie pie are usually vanilla buttercream or marshmallow cream. Vanilla buttercream contains milk, butter, vanilla extract and powdered sugar. Marshmallow typically contains marshmallow fluff, butter, vanilla extract and powdered sugar. Of course, you can get creative and add whatever filling you'd like!

Why are my snickerdoodle whoopie pies coming out flat?

If the cookies for your whoopie pie are flat, your batter was probably too thin or runny. Be sure to accurately measure each ingredient.

Do you need cream of tartar in snickerdoodles?

Although most snickerdoodle recipes use cream of tartar, you don't have. I used baking soda instead.

What are snickerdoodles?

Classic Snickerdoodles are sugar cookies rolled in cinnamon sugar. It's a classic cookie full of warm spices and nostalgia. They tend to have a cracked surface and can be either hard or soft, depending on the recipe.

Snickerdoodle Whoopie Pies

Preheat the oven to 350 degrees F. Line a baking sheet with parchment paper and set aside. Make the cinnamon sugar. Mix together cinnamon and sugar in a small bowl and set aside.
In a large mixing bowl, whisk together flour, baking powder, baking soda, cinnamon, and kosher salt.
In the bowl of a stand mixer fitted with the paddle attachment, cream together butter, oil, brown sugar, and sugar. Cream for 3 minutes, then add eggs, one at a time, ensuring that the first egg is incorporated prior to adding the next. (scrape down the sides of the bowl if needed) Then add vanilla extract and continue to mix.
Add sour cream and then add half of the flour mixture. Then add milk and add the remainder of the flour and mix until everything is fully incorporated.
Use a 1 tbsp cookie scoop to scoop out the batter and place onto the prepared baking sheets. Leave about 2 inches between each cookie.
Bake for 9-11 minutes. Allow the cookies to cool on the baking sheet for 5 minutes, then allow them to cool completely on a wire rack.
Make the buttercream - add butter to the bowl of a stand mixer fitted with the paddle attachment. Beat on medium speed for 3 minutes, then begin adding powdered sugar, one cup at a time.
Then add cinnamon, salt, and vanilla extract to the butter mixture and mix on high for 20 seconds. Reduce the speed to medium and add heavy cream one tablespoon at a time. Once all heavy cream is added, beat the icing on high speed again for 20 seconds.
Use a pastry brush to brush the tops of the whoopie pies with simple syrup and sprinkle with cinnamon-sugar mixture. If you don't have simple syrup, you can simply dunk the cookies into the cinnamon sugar.
Once the whoopie pies have completely cooled, add frosting to a piping bag and pipe buttercream onto the one whoopie pie and then top with another whoopie to make a cookie sandwich. Repeat for remaining pies.