Place the egg yolks, plain flour, butter, icing sugar and vanilla extract in the TM bowl. Mix 20 Sec/Speed 6.
Form into a ball. Wrap in clingfilm and chill for 30 minutes.
Unwrap and place on a floured surface and roll out to fit a rectangular tart dish. Line the tart dish with the pastry and prick a few holes with a fork. Chill for another 30 minutes.
Meanwhile, preheat the oven to 180C.
Remove the dish from the fridge and fill with greaseproof paper and baking beans (If you don’t have baking beans, use dry kidney beans, not the tin canned version). Bake in the oven for 15 minutes. Then remove the beans and greaseproof paper and bake for another 5 minutes. Leave to cool entirely on a wire cooling rack.
To make the ganache, place the chocolate in the cleaned TM bowl. Blitz 10 Sec/Speed 8. Scrape down and add the double cream and butter. Melt 4 Min/50C/Speed 3.
Pour in the cooled tart shell and sprinkle with the sea salt flakes. Leave to set in the fridge for at least 2 hours.