Preheat the oven to 180°C and line two baking trays with parchment.
Cream the butter and sugar until pale and fluffy.
Fold in the flour, cornflour, and salt until the mixture binds.
Knead the dough lightly, wrap in cling film, and chill for 15 minutes.
Boil raspberries and sugar in a pan for 5 minutes with lemon zest.
Strain the jam into a bowl and refrigerate until cold.
Roll the dough to 6mm thickness and cut out 48 circles.
Remove the centers of 24 circles using an apple corer.
Bake for 15 minutes at 180°C until the edges brown slightly.
Cool the biscuits on the tray for 10 minutes then move to a wire rack.
Beat softened butter, icing sugar, cream, and vanilla to make buttercream.
Mix royal icing sugar with water until smooth and place in a piping bag.
Assemble by placing jam and piped buttercream between a solid and a cut-out disc.
Pipe a smile and eyes onto each sandwich with royal icing.