Start by pouring the milk into the mug and put in the microwave to heat- until hot.
while the milk is heating, boil the water in a kettle.
when the water is ready, pour 3 teaspoons of the boiling water and 3 teaspoons of sugar into a small bowl/cup and mix well until saturated. Then add 1/2 teaspoon to 1 teaspoon of vanilla. Use more or less vanilla syrup depending on your preference.
when the milk and boiling water are both hot, add the tea bag into the mug with hot milk add boiling water so that the mug is almost filled. Pour in vanilla syrup and mix well. If you want too, froth the latte with a hand milk frothier.