Potato based chocolate cupcakes - Potato Nation

Ingredients

• 240 g (2 cups) potato flour
• 45 ml (3 tbsp) cocoa powder
• 10 ml (2 tbsp) baking powder
• Pinch of salt
• 100 ml butter, at room temperature
• 100 ml brown sugar
• 2 large eggs
• 10 ml (2 tsp) vanilla extract
• 150 ml cold coffee
• 50 g butter, at room temperature
• 100 g icing sugar
• 50 ml cocoa powder
• 5 ml (1 tsp) vanilla extract
• 10 ml (2 tsp) milk