Cream together the butter and sugar, starting slowly so as not to make the sugar balloon out of the bowl and beat until creamed together.
In a separate bowl mix together the flour, earl grey, poppy seeds and salt.
Beat the vanilla, lemon zest and juice into the butter mix then the flour. This will form a very stiff dough.
Form into a ball then flatten down (if you can flatten it a fair way do it now as it gets tough to roll out once chilled) and stick in the fridge for at least 3 hours to chill.
Place the dough between two sheets of grease proof paper and roll out until it's about ¼ inch thick. Place back in the fridge for 30 minutes.
Meanwhile preheat your oven to 150°C (130°C fan assisted) and line a couple of baking trays with grease proof paper.
Cut out into squares or use a biscuit cutter. Do not re-roll the scraps.
Prick the middle of each biscuits with a fork and transfer to the prepared baking sheets.
Place in the oven and bake for 20-25 until they start going gold on the edges.
Transfer to a wire rack and cool completely.
Recipe by The Bearded Bakery at http://www.thebeardedbakery.com/baking/cookies/lemon-earl-grey-poppyseed-shortbread-biscuits/