Chocolate whoopie pies

Ingredients

• Chocolate Whoppie Pies
• 60 grams butter, room temperature
• 2 1/2 brown sugar (250ml)
• 4 tbsp sunflower oil
• 1 egg
• 2 tsp vanilla sugar
• 4 dl (almost) flour (400ml)
• 1 1/2 dl cocoa unsweetened (150ml)
• 1 1/2 tsp baking powder
• 1/2 tsp salt
• 2 1/2 dl milk (250ml)
• Chocolate Filling
• 3 dl icing sugar (300ml)
• 1 dl cocoa (100ml)
• 4 tbsp butter, room temperature
• 3 tbsp cream
• 1 tsp vanilla sugar
• 1/2 tsp salt