I like thick-cut oats in this recipe since they make a more substantial cookie, but it's fine to substitute regular rolled oats if you have trouble finding thick-cut.
Make sure to spread the batter into a thin layer on the cookie sheet so the oats are in a single flat layer before you bake them.
The cookies will continue to spread during baking, so make sure to place the cookie batter at least two inches apart.
- 1/2 cup (115 g or 1 stick) unsalted butter
- 1 cup (220 g) packed dark brown sugar
- 2 tablespoons all-purpose flour
- 2 teaspoons vanilla extract
- 1/2 teaspoon kosher salt
- 1 large egg
- 1 1/2 cups (170 g) thick-cut rolled oats (or substitute regular rolled oats)
1 Preheat the oven to 350F. Line a baking sheet with parchment paper.
2 Melt the butter and sugar: Place the butter and brown sugar in medium saucepan over medium heat. Warm, stirring frequently, until the butter and brown sugar melt into a thick brown paste. It's fine if you see some streaks or puddles of separated butter; the butter and sugar don't need to fully combine.
3 Mix in the flour: Remove the pan from heat and stir in the flour, vanilla, and salt. The batter will be very thin. Set aside for 10 minutes to cool.
4 Mix in the egg and oats: Once the liquid has cooled (it’s OK if it is still warm, just not piping hot), add the egg and mix with a fork until incorporated. Add the oats and stir until well distributed.
5 Divide and shape the cookies: Spoon 1 tablespoon of the batter onto the baking sheet, leaving about 2 inches or more of space between each one. Use the back of a spoon to spread each cookie into a very thin circle, so the oats are in a single layer. If you don't have enough room on one baking sheet, bake the cookies in batches.
6 Bake the cookies: Bake in the oven for 8 minutes or until the edges of the cookies start to turn dark golden brown. Remove from the oven and let the cookies cool completely on the parchment paper. The cookies should peel easily from the parchment, but use an offset spatula if any are sticking.
Store in an airtight container for up to 3 days between sheets of parchment paper.