Chocolate Chip Woopie Pies - Martha White®

Ingredients

• non-stick Cooking Spray
• 2 (7.4 oz.) packages Martha White Chocolate Chip Muffin Mix
• 1/4 cup firmly packed dark brown sugar
• 4 tablespoons butter, melted
• 1 large egg, beaten
• 1 teaspoon vanilla extract
• 6 large marshmallows
• 4 tablespoons butter
• 3 tablespoons milk
• 2 cups powdered sugar
• 1/2 cup unsweetened cocoa powder