Preheat your oven to 350°F (175°C). Line a 9×13-inch baking pan with parchment paper, leaving an overhang on the sides for easy lifting later.

In a medium saucepan over low heat, gently melt the unsalted butter with the white chocolate chips, stirring continuously until smooth and glossy to avoid scorching.

Remove the saucepan from heat and transfer the warm mixture into a large mixing bowl. Stir in the granulated sugar, vanilla extract, and salt, whisking until well combined and the sugar begins to dissolve.

Add the eggs one at a time, mixing thoroughly after each addition to create a rich, smooth batter.

Gently fold in the all-purpose flour until just combined. A few streaks of flour are acceptable to prevent toughness in the bars.

Pour the batter into the prepared pan and spread evenly to the edges using a spatula for uniform baking.

Bake for 25 minutes, until edges start to turn golden and the center appears mostly set but still soft.

Remove the pan from oven and immediately sprinkle the toffee bits evenly over the partially baked bars.

Return to oven and bake for an additional 5 to 10 minutes until edges are golden brown and the center is fully set, with slightly melted toffee topping creating that brûlée effect.

Let the bars cool completely in the pan to allow them to set properly, which helps with slicing.

Use the parchment paper overhang to lift the slab from the pan, then cut into squares and enjoy!