Preheat the oven to 190°C and line a 12 hole cupcake tin with patty pans.
Combine the flour, sugar, butter, eggs and vanilla extract in a bowl and whisk together for 2 minutes.
Divide the mixture between the patty pans, then bake for 15-20 minutes. Transfer the cupcakes to a wire rack and leave to cool completely.
To make the butterscotch sauce, put the butter, cream, golden syrup and brown sugar in a small saucepan and boil for 2 minutes, stirring to dissolve the sugar.
Leave to cool completely. Whisk the cream with the icing sugar and vanilla until thick.
Remove the patty pans from the cupcakes and cut each one in half horizontally.
Add a spoonful of cream to the bottom half of each cupcake, drizzle over the butterscotch sauce and sandwich the cupcakes back together.