Pour 180 ml milk into a heatproof jug and add 1 drop vanilla essence. Microwave for 1 minute at 600W. (Alternatively heat the milk on the stove over a low heat until small bubbles form around the edges - do not let it boil)
Heat 2 tbsp water to 80 °C (176 °F) and pour it into a bowl. Sift in 1 ½ tsp matcha powder and whisk back and forth until foamy and the powder has dissolved.
Break 35 g white chocolate into small pieces. Take the milk from the microwave and add the chocolate to the jug. Mix and return to the microwave for 1 minute 600W (or until heated to your liking). If heating the milk on the stove, turn off the heat and add the chocolate, then stir until melted and combined.
Pour the matcha mixture into the milk and chocolate mixture and stir well.
Pour into a serving cup, then add your choice of toppings and an extra sprinkle of matcha powder. Enjoy!