Preheat your oven to 175°C and line a 20x20 cm (8x8 inch) baking pan with parchment paper.

In a mixing bowl, combine the flour, caster sugar, and salt. Add the softened butter and mix until it forms a crumbly dough.

Press the dough evenly into the lined baking pan.

Bake for 22 minutes or until the edges are golden. Allow it to cool completely.

Slice into 16 even rectangles.

In a saucepan, combine the sweetened condensed milk, brown sugar and butter.

Cook over medium-low heat, stirring constantly, for 10–15 minutes until the mixture thickens and turns a golden caramel colour. Be careful not to let it burn.

Let the caramel cool slightly and spread onto the shortbread sticks. Let the caramel set before coating in chocolate.

Melt the chocolate in a microwave-safe bowl in 30-second increments, stirring after each increment until smooth.

Cover the the caramel shortbread sticks with melted chocolate.

Allow the chocolate to set at room temperature for a few minutes, then refrigerate for an additional 20–30 minutes to fully set.

Step 4: Once fully set, enjoy your homemade Twix bars!