Allow the pastry to defrost until easy to unroll, but not soft.
Mix the sugar and cinnamon together then sprinkle over the surface of the pastry.
Firmly roll up the pastry starting from the short end to encase the sugar and cinnamon. Wrap in baking paper, chill until firm.
To prepare the custard, put the egg yolks, whole egg, sugar, cornflour and vanilla in a saucepan, whisk together until smooth, gradually adding cream and milk.
Place saucepan over gentle heat; cook stirring frequently with a spatula. Continue until the mixture thickens but do not boil. Remove from heat, cover surface with cling wrap to prevent a skin from forming and leave to cool.
Preheat oven to 200°C. Lightly grease a 12-hole muffin tin.
Take pastry roll from the fridge and cut into 12 x 2.5cm rounds.
Working quickly, place pastry rounds in muffin holes then using your thumbs work the pastry upwards to line the mould. You may need to lightly flour your fingers. Repeat this process with all 12 pastry rounds.
Pour prepared custard into pastry cases, filling to the top.
Place into preheated oven, cook for 20-25 minutes or until pastry and custard is golden.
Leave the tarts to cool in the tin for 5 minutes then transfer tarts to a wire rack to cool completely.
