To start, gather your ingredients. In the bowl of a stand mixer fitted with the paddle attachment (or a large mixing bowl and hand mixer), add the egg, butter, light brown sugar, granulated sugar, and vanilla extract. Beat on medium-high speed for about 5 minutes until the mixture is light and fluffy. You want it to be creamy and well combined, showing a light yellow color.
Next, stop the mixer and scrape down the sides of the bowl to ensure everything is well mixed. Now, add in the old-fashioned oats, all-purpose flour, cinnamon, ground nutmeg, baking soda, and a pinch of salt if you’re using it. Beat on low speed just until combined, being careful not to overmix. The dough should come together nicely, showing some texture from the oats.
Now, it’s time to fold in the star ingredient! Add the butterscotch chips into the dough and beat for just a moment to incorporate. You want the chips evenly distributed throughout the dough, adding bursts of sweetness in every bite.
Using a 2-inch medium cookie scoop (about 2 tablespoons), form dough mounds. I made around 20 mounds, but you can adjust the size as you like. Place the mounds on a large plate and flatten them slightly. Cover the plate with plastic wrap and refrigerate for at least 2 hours, and up to 5 days before baking. This chilling step is crucial, as it helps the cookies maintain their shape while baking.
When you’re ready to bake, preheat your oven to 350°F (175°C). Line 2 baking sheets with Silpat Non-Stick Baking Mats, parchment paper, or spray with cooking spray. Make sure the baking sheets are prepared as this will help prevent sticking.
Now, arrange the chilled dough mounds on the prepared baking sheets, spaced about 2 inches apart. I usually bake about 8 mounds per sheet to ensure even baking. It’s important not to crowd the cookies, as they will spread while baking.
Bake in your preheated oven for 9 to 10 minutes. Look for the edges to be set and the tops to be barely set, even if they’re slightly underbaked in the center. Cookies may not appear fully done, but they will firm up as they cool. Be careful not to overbake, as this can result in dry cookies.
Once baked, allow the cookies to cool on the baking sheets for about 5 minutes. This allows them to firm up slightly before transferring them to a wire rack to finish cooling. The cookies will continue to set as they cool, giving you perfectly soft and chewy treats.
