Gobs (a.k.a. Whoopie Pies)

INGREDIENTS

• :
• 2 cups all-purpose flour
• ½ cup unsweetened cocoa powder
• 1 teaspoon baking soda
• ¼ teaspoon salt
• ½ cup vegetable shortening
• 1 cup granulated sugar
• 1 egg + 1 egg yolk
• 1 teaspoon vanilla extract
• 1 cup buttermilk
• 1 cup hot water
• 1½ cups marshmallow fluff
• 1¼ cups vegetable shortening
• 1 cup powdered sugar
• 1 tablepsoon vanilla extract