Preheat the oven to 180ºC (356 °F). Line two baking sheets with baking parchment.
Place the butter and sugar into the mixer and beat well until light and fluffy.
Sieve the flour and cornflour then add to the butter and sugar mixture and mix well.
Place the mixture into a piping bag with a star nozzle attached and pipe into circles in the baking parchment.
Place in the oven for between 12-15 minutes until then turn a pale golden colour.
Cool on the baking tray for a few minutes then transfer to a wire cooling rack.
Once cool make the buttercream by beating the butter, sugar and vanilla until light and fluffy then transfer to a piping bag with a star nozzle fitted.
Spread a little jam on the flat size of one whirl, pipe the buttercream on top then top with another whirl.
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