Preheat oven to 220°C (200°C fan)
Line a baking tray with baking paper.
Cream together the butter and caster sugar until fluffy and light.
Add the flour, Earl Grey tea, vanilla extract, dried lavender and sea salt until well combined.
On a floured surface, roll the dough into the desired thickness and cut into circles with a cookie cutter.
Place the cut out shortbread dough onto the prepared baking tray, and into the refrigerator for one hour. This will allow the batter to set and the shortbread to bake evenly.
Prick the top of the shortbread with a fork.
Place into the preheated and bake for 15-20 minutes or until slightly golden.
Remove the shortbread and lay to cool on a wire rack.