Crunchy Pecan-Toffee Cookies

Combine flour, baking soda, and salt in a medium bowl; whisk until well combined.

Place butter and brown sugar in a large bowl and beat with an electric mixer until light and fluffy, about 3 minutes.

Add egg whites and vanilla extract, and beat for 1 more minute.

Gradually add flour mixture to the bowl and mix until completely combined.

Fold in pecans and toffee bits until all ingredients are well incorporated.

Move the bowl to the refrigerator and chill for at least 30 minutes.

Preheat the oven to 375 degrees F (190 degrees C).

Line 2 large baking sheets with parchment paper and set aside.

Scoop dough into heaping tablespoon-sized balls with a spoon or cookie scoop.

Place dough balls about 2 inches apart on the prepared baking sheet and flatten just slightly with the palm of your hand.

Bake in the preheated oven until edges are set and lightly browned, 10 to 12 minutes.

Let cookies cool on the baking sheet for 1 minute, then transfer to a wire rack to cool completely.