Instructions

1. Preheat oven to 180 C (350 F) standard / 160 C (320 F) fan-forced. Line a 12-hole muffin pan with cupcake liners.
2. In a large mixing bowl, beat together butter, sugar and vanilla using an electric mixer on medium speed until pale and creamy – this will take a couple of minutes. 
3. Add egg and beat briefly until combined. In a separate bowl, sift together flour, baking powder and salt. Add half the flour mixture and all the milk and slowly mix together on a low speed.
4. Add the rest of the flour and the sour cream and mix briefly until smooth and creamy. The mixture will be thick.
5. Spoon out the cake batter in your prepared liners (approximately 2/3 full) and bake in the oven for approximately 18-20 minutes or until golden. Leave to cool completely on a wire rack.
6. To make the filling, add cream to a large mixing bowl. Whisk using an electric mixer until cream is thick and stiff peaks form. You’ll know it’s ready when you can hold the bowl of cream upside down without anything moving. 
7. Using a small knife, carefully cut circles of cake out of each cupcake – keeping the spare piece of cake intact (don’t eat it yet!).
8. Fill each cupcake with a generous amount of whipped cream. Then divide the extra piece of cake into two and arrange on top of the cream so it looks like butterfly wings. Repeat with remaining cupcakes. 
9. Generously dust cupcakes with icing sugar to serve.