Preheat the oven to 160°C.
Whisk the egg whites until stiff. Add the caster sugar to the the egg whites and continue whisking until you have stiff, glossy peaks of meringue.
Fold the ground almonds, vanilla and icing sugar into the meringue mixture. Cut and fold the mixture with a spatula until it is smooth, shiny and has reached the ribbon stage. Add the food coloring and ripple through the mixture.
Use a piping bag to pipe this mixture on to a baking mat or lined baking tray. Allow the macaroons to rest at room temperature for 10-15 minutes until the macaroon shells are no longer sticky to touch. Bake in the oven for about 10 minutes. Allow to cool before filling.
Mix together the egg yolks, caster sugar and the cornflour.
Place the milk in a saucepan and bring to the boil. Once boiling, add the milk to the egg yolk mixture a little at a time. Return to the pan and whisk over a medium heat for 3-4 minutes, gently bringing it back to the boil. Place the cream in a bowl and allow to cool.
Fold the raspberry jam into the cooled cream to give a rippled effect and then transfer to a piping bag.
Pipe the cream on to half of the macaroon shells and then sandwich the two halves together to finish.
«Add the food coloring at the last possible moment to make sure the shells have a good rippled effect.»