2 cups old-fashioned rolled oats

1 cup chocolate chips or chunks

1. Arrange 2 racks to divide the oven into thirds and heat to 350 F. Line 2 baking sheets with parchment paper.

2. Melt the butter in 30-second intervals in a large microwave-safe bowl until completely melted, 1 to 2 minutes total. Set aside to cool for at least 5 minutes.

3. Whisk the flour, cornstarch, baking powder, cinnamon and salt together in a medium bowl; set aside.

4. Add the brown and granulated sugars, egg and vanilla to the butter, and whisk until completely smooth.

5. Add the oats, followed by the flour mixture. Fold together with a rubber spatula until mostly homogenous. Fold in the chocolate until no dry streaks of flour remain.

6. Scoop the dough with a small cookie scoop or spoon into 2-tablespoon portions on the prepared baking sheets, placing them about an inch apart, 8 cookies per baking sheet.

7. Bake until the cookies have spread, are just beginning to brown at the edges, and their centers are just set, 10 to 12 minutes.

8. Let the cookies cool for 1 minute on the baking sheets. Transfer to a wire rack to cool completely. Repeat baking the remaining cookie dough; you can reuse the parchment on cooled baking sheets.

Recipe notes: Store in an airtight container at room temperature for up to four days.

(Meghan Splawn is associate food editor for TheKitchn.com, a nationally known blog for people who love food and home cooking. Submit any comments or questions to editorial@thekitchn.com.)