Fruit muffins and whoopie pies

Ingredients

• 125 g butter
• 165 g (¾ cup) caster sugar
• 1 tsp vanilla paste
• 185 ml (¾ cup) buttermilk
• 2 eggs, lightly beaten
• 300 g (2 cups) self-raising flour
• 75 g (½ cup) plain flour
• ½ tsp bi-carb soda
• 100 g fruit, we used raspberries
• Icing sugar, optional
• 1 x vanilla muffin mix without the fruit
• 100 g raspberries
• 200 g butter, softened
• 320 g (2 cups) icing sugar, sifted
• 1 ½ tsp lemon juice
• 1 tbsp milk