Triangle Cheese Cake

This recipe is from my mother, and has traveled in my recipe book for years, and only this past
weekend (25 March 2017) did I finally get around to making it.  Mother, why did you never make this when I was a kid?

125g Butter
100g Castor Sugar
1 Egg Yolk
250g Cream Cheese
10ml Vanilla Essence
1 1/2 pack Tennis Biscuits
250g Dark Chocolate

- Cream the butter and sugar fluffy.

- Add the yolk, mix well, then add the cheese and vanilla.

- On a sheet of foil, pack a grid of 3x4 tennis biscuits.

- Spread 1/3 to 1/2 the mixture over the biscuits.

- Pack another grid of tennis biscuits.

- Spread the rest of the mixture on the biscuits.

  ( - OPTIONAL:  sprinkle glazed cherries, or chocolate shavings down the middel row. )

- Gather the foil up to form a triangle and freeze 12 - 24 hours.

- Melt the chocolate and cover the log with the chocolate.  Wrap the foil again and store in the freezer.