To make the crust

Cup of Yum
1. Preheat the oven to 180C/356F/gas mark 4.
2. Gently crush the cornflakes into smaller pieces, making sure to maintain a chunky texture rather than turning them into fine dust. You can leave a few large pieces in tact.
3. In a large bowl, mix the crushed cornflakes with the melted butter, sugar, pinch of salt and cinnamon.
4. Press the cornflake mixture firmly into the bottom of a baking dish that is approximately 20cm x 30cm in size. You can also use a loose-bottomed tart tin.Do your best to press the cornflakes up the sides of the baking dish as high as possible, although it might not stick well due to its dry nature. It's unlikely to go higher than a quarter of the way, but if you manage to get it halfway up, that's an excellent accomplishment!
5. Bake the crust for 10 minutes, then set it aside to cool down. Keep the oven on at the same temperature, as you will need it in a short while to bake the meringue.

For the custard filling

1. While the crust is baking, whisk together the sugar, plain flour, 6 x egg yolks, 250ml of the milk and the vanilla extract. You can use a hand whisk for this.
2. In a large saucepan over medium heat, warm up the remaining milk (1000ml) until it is just below simmering point. Watch for small bubbles forming on the side of the pan and a bit of steam rising up. Once you notice these signs, it's time to remove the milk from the heat.
3. Gradually whisk the warm milk into the egg mixture.
4. Pour the custard mixture back into the saucepan. Place it over a medium-low heat and continue whisking until the custard thickens and begins to approach a boiling point. Once it reaches this point, remove the saucepan from the heat.
5. Pour the custard over the tart case in the baking dish and set aside to cool whilst you get on with the meringue.

To make the meringue topping

1. In a large grease-free bowl, whisk together the egg whites and the cream of tartar until light and foamy. You can use a stand mixer or an electric hand mixer for this.
2. Begin adding the caster sugar to the egg whites, adding 2-3 tablespoons at a time. Whisk for approximately 1 minute between each addition. Continue whisking until the meringue forms stiff peaks and takes on a glossy, bright white appearance.
3. Spoon the meringue over the custard layer.
4. Bake for 12-15 minutes until the meringue is a light golden brown.
5. Leave to cool completely before serving. Use a sharp knife to cut squares.