Homemade Oatmeal Creme Pies

Name: Homemade Oatmeal Creme Pies
Prep time: 10 min
Cook time: 12 min
Total time: 22 min
Cuisine: American
Ingredients: 1/2 cup unsalted butter (1 stick); 3/4 cup light brown sugar; 1/2 cup powdered sugar; 1 large egg; 1 teaspoon vanilla extract; 1/4 teaspoon baking soda; 1/2 teaspoon salt; 1 tablespoon cornstarch; 1 teaspoon unsweetened cocoa powder ((this is for color, you can omit if desired)); 1 cup quick oats; 1/2 cup raisins; 1 cup all-purpose flour ((not packed, just scooped and leveled with a knife)); 2 tablespoons milk; 1/2 cup unsalted butter (softened); 1/2 teaspoon vanilla extract; 1/4 teaspoon salt; 1 cup powdered sugar; 7 oz. marshmallow fluff