Preheat and prepare. Heat your oven to 180°C (160°C fan). Line a 20cm x 20cm square baking tin with a long strip of parchment paper, leaving an overhang on two opposite sides. This creates ‘handles’ for lifting the cooked bars out later.

Make the shortbread crust. In a large bowl, rub the cold butter cubes into the flour, caster sugar, and salt using your fingertips until the mixture resembles fine breadcrumbs. The texture should feel sandy and slightly damp. Press this mixture firmly and evenly into the base of the prepared tin. Use the bottom of a glass to get it really flat.

Blind bake the crust. Prick the crust all over with a fork. Bake for 15-18 minutes, until the edges are a very pale golden colour and the surface feels dry to the touch. The smell at this stage is pure, buttery shortbread.

Prepare the filling. While the crust bakes, whisk the brown sugar, golden syrup, eggs, melted butter, vanilla, and salt together in a medium saucepan over low heat. Stir continuously for 2-3 minutes until the mixture is smooth, glossy, and slightly warm. Do not let it bubble. You’ll see the sugar dissolve completely, and the mixture will look like thick caramel.

Assemble the bars. Scatter the chopped pecans evenly over the hot, pre-baked crust. Pour the warm filling slowly and evenly over the nuts. Give the tin a gentle tap on the worktop to release any air bubbles.

Bake to perfection. Return the tin to the oven and bake for 18-22 minutes. The bars are ready when the filling is set around the edges but still has a slight jiggle in the very centre – similar to a baked cheesecake. The surface will be a deep, burnished gold, and the kitchen will smell of toasted nuts and caramel.

Cool completely. Place the tin on a wire cooling rack. This is the hardest part. Let the bars cool in the tin for at least 20 minutes, then use the parchment handles to lift them out. Allow them to cool completely for another 30 minutes before slicing. Warm bars will crumble; patience gives you clean, neat squares.