Oatmeal Whoopie Pies

Ingredients

• 2 cups packed brown sugar
• 0.75 cups unsalted butter , softened
• 2 large eggs
• 2.5 cups all-purpose flour
• 1 teaspoon ground cinnamon
• 1 teaspoon baking powder
• 1 teaspoon baking soda
• 0.5 teaspoons salt
• 3 tablespoons boiling water
• 2 cups quick cooking oats

Instructions

1. 1

   Preheat the oven to 350 degrees F (175 degrees C). Lightly grease 2 baking sheets.

2. 2

   Make the cookies: Beat brown sugar and butter in a large bowl with an electric mixer until light and fluffy. Add eggs and mix well.

3. 3

   Mix together flour, cinnamon, baking powder, baking soda, and salt in a separate bowl. Add flour mixture to wet ingredients in 2 batches, alternating with boiling water, mixing batter after each addition until well combined. Stir in oats.

4. 4

   Drop spoonfuls of dough 2 inches apart onto the prepared baking sheets.

5. 5

   Bake in the preheated oven for 10 to 12 minutes, switching racks halfway through. Remove from the oven and transfer to wire racks to cool.

6. 6

   While the cookies are cooling, make the filling: Beat 1 cup confectioners' sugar, egg white, milk, and vanilla until combined. Beat in shortening and remaining 1 cup confectioners' sugar until light and creamy.

7. 7

   Spread filling onto 1/2 of the cooled cookies, then sandwich with remaining cookies.