- 6oz (3/4 Cup) Unsalted Butter, softened to room temperature
- 100 grams (1/2 Cup) Granulated/ Caster Sugar
- 150 grams (3/4 Cup) Light Brown Sugar
- 1 Large Egg + 1 Large Egg Yolk, at room temperature
- 2 Teaspoons Pure Vanilla Extract
- 281 grams (2 1/4 Cups) All-Purpose/ Plain Flour
- 1/2 Teaspoon Salt
- 3/4 Teaspoon Baking Soda
- 1 Teaspoon Cornstarch/ Cornflour
- 270 grams (1 1/2 Cups) Chocolate Chips or Chunks
- Preheat oven to 350F/180C and line with foil and lightly grease an 8 or 9 inch baking pan.
- In a medium-sized bowl whisk together the flour, baking soda, salt, and cornstarch. Set aside.
- In the bowl of an electric mixer combine butter and sugars. Mix on medium for around 2 minutes, until light and fluffy. Make sure to scrape down the sides of the bowl to ensure all is combined.
- Stir in vanilla, egg, and egg yolk, making sure to mix until fully combined. Scrape down the sides of the bowl again.
- Gently fold in dry ingredients and chocolate chunks until just combined. I like to save a few of the chocolate pieces to place on top of the bars before baking, just for aesthetics.
- Pour cookie dough into prepared pan and gently press into an even layer. Bake the cookie bars for 19-26 minutes*. The edges should be golden brown and pulling from the edge of the pan, the center will still giggle a bit.
- Let the bars cool in the pan on a wire rack for 20 minutes then slice and serve. Store leftovers in an air-tight container for up to 5 days.
*For thick bars as pictured I used an 8-inch pan and baked for 24-26 minutes. For thinner bars bake in a 9-inch pan and bake for 19-22 minutes. The bars should look very set around the edges and not totally set in the center, still have a little sheen. If you do not like a softer almost gooey cookie center bake the bars for an additional 3-5 minutes, just watch carefully not to burn the bars.
- Prep Time: 10
- Cook Time: 30
- Category: Dessert
- Method: Bake
- Cuisine: American
Keywords: chocolate chip cookie bar recipe, chocolate chip blondies, chocolate chunk cookie bars