Directions:

1. Preheat the oven to 350°F.
2. Spray a 9x13 baking dish with cooking spray and line with parchment paper. The spray will help the paper adhere to the contours of the dish. Leave some overhang for easy removal.
3. Place candy bar pieces in a bowl in the freezer until ready to add to the dough.
4. In a bowl, whisk together the flour, salt and baking soda. Set aside.
5. In a large stand mixer, beat the butter with the paddle attachment for 2 minutes on medium speed.
6. Add the sugar to the butter and beat on low, gradually increasing the speed until the butter mixture is light and fluffy (2-4 minutes). Scrape down the sides a few times to make sure every part of the butter and sugar is mixed thoroughly.
7. Add the eggs and vanilla to the batter. Mix for another minute.
8. On low mixing speed, gradually add the flour mixture a bit at a time, upping the speed after each addition until it is all combined before lowering it again. .
9. Add 2 cups of the chopped candy bars and mix in for 10-15 seconds.
10. Transfer cookie dough to the prepared dish in large spoonfuls. Press down until it covers the whole dish in an even layer.
11. Bake for 35-40 minutes. The top of the cookie bars should be a deep golden-brown colour. If the top is starting to brown too much, cover the top of the dish with aluminum.
12. Remove from the oven and immediately press the remaining half cup of chocolate bar pieces into the top of the dough. Let the bars cool completely before removing from the dish. Use the parchment paper sides to lift the bars out of the dish to a cutting board.
13. Using a large knife, cut into squares and store in a container.