Preheat the oven to 170C/350F/Gas 4. Grease the financier moulds and set onto a baking tray.
Sift the flour and baking powder into a bowl. Add the icing sugar and ground almonds and stir to mix.
Add the egg whites and whisk everything thoroughly for one minute with a wire whisk.
Heat the butter in a small pan until the solids just start to brown. Tip the butter into the financier mix through a tea strainer.
Add the finely shredded basil leaves.
Leave the mixture to rest for 5-10 minutes.
Transfer the mixture to a piping bag fitted with a 1cm/½in plain nozzle.
Pipe into the silicone financier moulds, filling them three-quarters full.
Place two raspberries (if small) or one (if large) cut into two halves into the basil financiers.
Bake for 10-12 minutes until just golden-brown (may need up to 15 minutes to cook).
Remove from the oven and leave the baked financiers in their moulds for 1-2 minutes before turning out onto a wire rack to finish cooling.
When cooled, lightly dust the financiers with sifted icing sugar.