In a medium bowl, mix matcha powder and hot water and set aside.
In a saucepan, mix together egg yolks and sugar. Then gradually pour in milk, mixing well. Place saucepan over low heat and stir mixture until it thickens. Remove thickened mixture from the heat and let cool.
Transfer cooled egg mixture to a large bowl, and add matcha mixture. Mix well. Gently stir in whipped double cream.
Pour this ice cream batter into an ice cream maker and churn for 20 minutes. Place in a plastic container and freeze for at least 2 hours. Remove mixture from freezer, stir well, and re-freeze for another 2 hours.
Remove again from freezer to stir thoroughly, and then replace the ice cream to freeze for a final 8 hours, or overnight ( until completely set). The multiple freezing help create a creamier texture.
Once ice cream is set, add 2-3 scoops to a serving bowl and drizzle with fudge sauce. Decorate with cherries and wafer biscuits to serve.