1. For the pancake batter place the flour, milk, vanilla and egg yolks into a medium-sized bowl and whisk together until smooth. Set aside for the moment.
2. Japanese pancakes are incredibly light and rely on whipped egg whites so this is the most important step. Place the egg whites, cream of tartar and salt into a large bowl and whisk (with a clean whisk) until the mixture is foamy. Slowly rain in the sugar whilst whisking the whites. Once all of the sugar has been added continue whisking until the meringue holds soft peaks. It is important the meringue is whisked to the right stage. Too little, the pancakes will spread, and whisked too much the whites will be hard to fold into the batter and you’ll knock out too much air.
3. Working in three additions fold the whites into the batter, folding just until combined. Scrape the batter into a piping bag. Heat a non-stick frying pan over low heat and brush with kitchen roll dipped in a little vegetable oil. Pipe tall mounds of batter, about 7-8 cm in diameter. Spoon 2 tsp water into the frying pan and place a lid on the pan for 2-3 minutes, until the water has cooked off and the pancakes are golden on the base. This steams and sets the top of the pancakes whilst the bottom browns. Remove the lid and flip the pancakes, adding another 2 tsp water and replacing the lid and cooking for another 2-3 minutes.
4. To serve, top the pancakes with a little piece of butter and a generous drizzle of Lyle’s Golden Syrup