Nana Bessie's Chocolate Whoopie Pies

Preheat your oven to 350 degrees Fahrenheit (175 degrees Celsius). Cover baking sheets with parchment paper for easy cleanup.

To create a batch of cookies, combine 2/3 cup of vegetable shortening with 2 cups of sugar in a large mixing container using an electric mixer until the mixture reaches a smooth consistency. Incorporate eggs and 2 teaspoons of vanilla extract into the mixture until everything is fully incorporated. Combine 4 cups of flour, cocoa powder, and baking soda in a separate bowl until they are well mixed. Gradually add the flour mixture to the shortening mixture in multiple stages, alternating with milk as needed. Mix the dough just until it reaches a smooth state.

Place spoonfuls of the dough onto the prepared baking sheets, leaving about 2 inches between each cookie to ensure they retain their round shape. This recipe should produce approximately 48 cookies.

Bake the cookies in the preheated oven until they are set in the middle, taking 15 to 20 minutes. Keep a close eye on them to avoid burning. Allow the cookies to cool for several minutes before removing them from the baking sheets and finishing their cooling process on racks.

To prepare the filling, pour 3 cups of milk into a saucepan over low heat and whisk in 9 tablespoons of flour until the mixture is smooth. Bring the mixture to a simmer, constantly whisking, until it reaches a thick and creamy consistency, similar to pudding, approximately 3 minutes. Place the cooled filling in the refrigerator for about 30 minutes to allow it to chill.

In a large mixing container, combine 1 1/2 cup of vegetable shortening with butter until they are fully incorporated. Incorporate 2 1/4 cup of sugar and 1 tablespoon vanilla extract into the mixture until everything is well combined. Gradually add the cooled milk mixture to the butter mixture until it reaches a smooth and fluffy state, taking 1 to 2 minutes.

Select two cookies of similar size and spread a generous layer of filling on the flat side of one cookie; top with the remaining cookie. Repeat this process with the remaining cookies and frosting.