Sounds posh, but it's just the French version of shortbread!
These are little teeny biscuits where all the mixing is done by food processor.
Chop 115g room temperature butter into cubes, and blitz until creamy. Then add 50g caster sugar and 1/4 tsp vanilla extract and blitz again until mixed. Add 160g plain flour and give it another blitz.
You should have a crumbly mix like this.
Make it into a dough by pressing it all together, then roll into 2 long sausages - about 2 inches thick.
Sprinkle brown sugar onto your surface and roll the sausages in it.
Then chop into slices - about an inch thick.
Spread onto baking parchment and bake for 20 minutes at 180 deg c.
Perfect served with a mocha for that coffee shop experience!