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Gather all ingredients. Preheat the oven to 350 degrees F (175 degrees C). Arrange racks in the upper and lower thirds of the oven. Line 4 baking sheets with parchment paper.
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Whisk together flour, baking soda, and salt in a small bowl.
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Beat butter with an electric mixer in a bowl until creamy, about 30 seconds. Add brown sugar and white sugar; beat until light and fluffy, 1 to 2 minutes. Beat in egg, egg yolk, and vanilla until combined. Gradually beat in flour mixture until just incorporated.
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Stir in chocolate chips.
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Divide dough in fourths, wrap each portion in plastic wrap and chill dough for at least 1 1/2 hours and up to 24 hours.
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Roll 1 portion of dough at a time into a rope about 1/2 inch in diameter on a lightly floured surface. Cut crosswise into about 1/2-inch pieces. A bench scraper is helpful for this. Arrange pieces on a prepared baking sheet, spacing slightly apart. Repeat with remaining dough.
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Bake 2 sheets at a time until cookies are golden brown, about 8 to 9 minutes, rotating pans halfway through. Let cookies cool completely on the sheets before serving.