Oatmeal Scotchie Whoopie Pies

Preheat oven to 350ºF. In a stand mixer, cream butter with brown sugar until light and fluffy. Beat in eggs, salt, cinnamon, baking powder, boiling water, baking soda and flour. Mix to combine. Stir in the oats.

Drop cookies, using a cookie scoop to achieve a uniform size, onto lightly greased cookie sheets. Bake for 10-12 minutes. Cool completely before preparing the filling.

For the filling, carefully separate an egg, and in a stand mixer, beat egg white on high for up to 20 minutes or until very light and frothy. Mix in milk, vanilla and 1 cup of powdered sugar. Beat in shortening and remaining sugar until light and fluffy. (You can add more milk if it gets too stiff, or more sugar if it is too runny.)

Add a thick layer of filling to the bottom of one cookie and top with the bottom of another cookie. Refrigerate until serving time, then set out 15 minutes beforehand to allow cookies to start to soften.

Enjoy. These are amazing!