Easy - for beginners
In pot heat milk, butter and vanilla essence In medium bowl mix flour, cornflour, sugar and eggs with electric mixer. When milk has boiled add to flour mixture and mix well. Return mixture to pot and place on low heat. Stir till thick - lumps will form When thick remove from heat and beat with electric mixer till very smooth. Pour into shell of tennis/nice biscuits and sprinkle with cinnamon.
I am greedy and like lots of filling so I always double up on the filling. As seen in photo, I guess you can tell I like lots of it.