01 - Preheat the oven to 350°F (Gas Mark 4).
02 - Rub cold butter into flour and salt in a mixing bowl until the texture resembles breadcrumbs.
03 - Add cold water a tablespoon at a time, mixing until the dough begins to come together. Shape into a disc, wrap in plastic wrap, and refrigerate for 15 minutes.
04 - Roll out the pastry on a lightly floured surface to fit a 9-inch tart tin. Line the tin with the pastry, trim the excess, and prick the base with a fork to prevent bubbling.
05 - Place baking paper over the pastry and fill with baking beans. Blind bake for 15 minutes, remove paper and beans, then bake an additional 5 minutes until lightly golden.
06 - Once the pastry is baked, evenly spread strawberry jam over the warm base.
07 - Melt unsalted butter, light corn syrup, and light brown sugar together in a saucepan over low heat, stirring until smooth and combined.
08 - Remove mixture from heat and fold in cornflakes, ensuring they are thoroughly coated with syrup mixture.
09 - Gently spoon and spread the cornflake mixture over the jam layer, covering evenly without compacting.
10 - Bake the assembled tart for 10 minutes or until the cornflake topping is golden and set.
11 - Allow the tart to cool slightly before slicing. Serve warm or at room temperature, ideally accompanied by custard.