In a stand mixer, cream butter and sugar well together and add the egg, before beating well.
Add all other ingredients and mix until you have a stiff dough.
Press into a tart or pie dish.
Bake blind for 15 minutes at 350°F (use wax paper to cover the pastry and place dry beans/rice, or pie weights, over the paper to weight the pastry down). Then remove the paper and beans/rice and bake for an additional 5 minutes until light brown.
Filling:
In a medium pot, bring milk to a gentle boil.
In a medium bowl, beat eggs well and add sugar, flour, corn starch and salt. Mix well.
Pour boiling milk into the mixture and stir well.
Return to pot on the stove and stir for 10-12 minutes on medium heat until the mixture thickens.
Add butter and vanilla essence and mix through, then pour into cooked shell.
Allow to cool in the fridge. Sprinkle with cinnamon before serving.