Preheat your oven to 350°F (175°C) and prepare a 9x13-inch baking pan by greasing it lightly with butter or non-stick spray.

In a large mixing bowl, sift together the all-purpose flour, packed brown sugar, and granulated sugar. Stir thoroughly to combine and eliminate lumps.

Melt the butter and pour it into the dry mixture, then mix with a spatula until crumbly.

Add the eggs and vanilla extract, mixing well until a cohesive dough forms.

Fold in the toffee bits, ensuring they are evenly distributed throughout the mixture.

Transfer the cookie dough to the greased baking pan, spreading it evenly and pressing down gently.

Bake in the preheated oven for 25-30 minutes until the edges are golden and the center is set but slightly soft.

Once baked, cool completely on a wire rack before cutting into squares or rectangles.