Wheaty banana muffins

Ingredients

• 1 banana
• 1 tablespoon lemon juice
• 1 1/2 cup self-raising flour
• 1/2 cup firmly packed brown sugar
• 1 cup crushed weet-bix
• 1 cup (280g) mashed banana
• 1/2 cup buttermilk
• 80 grams butter, melted
• 1 egg, beaten lightly
• 1 tablespoon honey
• 2 teaspoons milk
• 1/2 cup icing sugar