Choc-Oat-Chip Whoopie Pies - The BakerMama

Ingredients

• 1 cup (2 sticks) unsalted butter, softened
• 1/2 cup granulated sugar
• 1/2 cup dark brown sugar
• 1 large egg
• 1/2 teaspoon pure vanilla extract
• 1 cup all-purpose flour
• 1 cup quick cooking oats
• 1 (3.4 ounce) box vanilla instant pudding mix
• 1 teaspoon baking soda
• 1 cup chocolate chips
• Filling:
• 1/2 cup (1 stick) unsalted butter, softened
• 1 cup marshmallow fluff
• 3 cups powdered sugar
• 1-2 teaspoons milk, if needed