Line a rough 15cm x 24cm x 4cm (6in x 9½in x 1½in) roasting tin with baking parchment. Heat sugar and milk over medium-high heat in a heavy-based pan, stirring occasionally to help dissolve the sugar (about 2min). When it has, stir in the condensed milk and salt, and heat until bubbles appear around the edges of the pan. Bubble for 7-8min, whisking constantly to avoid the mixture scorching - it should be a light butterscotch colour.
Step 2
Take the pan off the heat, add the vanilla and beat with a whisk for exactly 2min (you will see the mixture thicken slightly). Quickly and carefully empty into the prepared tin. Smooth the surface.
Step 3
Set aside for 5min, or until just hardened. Then lift out of the tin using the baking parchment, and mark into 45 squares (cutting halfway down into the tablet). If the mixture sticks to the knife, let the tablet set for another minute. With the help of the baking parchment, return tablet to the tin and leave to cool completely.
Step 4
To serve, break the tablet into its marked squares. Any leftover tablet will keep in a tin or paper bag at room temperature for up to two weeks.
Prepare to end of step 3 up to a week ahead. Once solid, wrap the tin in baking parchment (it doesn't need to be airtight) and store at room temperature. Break into squares to serve.
An experienced and highly skilled team of food writers, stylists and digital content producers, the Good Housekeeping Cookery Team is a close-knit squad of food obsessives. Cookery Editor Emma Franklin is our resident chilli obsessive and barbecue expert, who spends an inordinate amount of time on holidays poking round the local supermarkets seeking out new and exciting foods. Senior Cookery Writer Alice Shields is a former pastry chef and baking fanatic who loves making bread and would have peanut butter with everything if she could. Her favourite carb is pasta, and our vibrant green spaghetti is her weeknight go-to. Lover of all things savoury, Senior Cookery Writer Grace Evans can be found eating crispy corn and nocellara olives at every opportunity, and will take the cheeseboard over dessert any time (though she cannot resist a slice of tres leches cake). With a wealth of professional kitchen know-how, culinary training and years of experience between them, they are all dedicated to ensuring every Good Housekeeping recipe is the best it can be, so you can trust they’ll work (and if they don’t – we’ll have the answer for why*) every time (*90% of the time the answer is: “buy an separate oven thermometer”!).
