Preheat oven to 350F. Line a baking sheet with a silpat liner or parchment paper.
Melt the butter in a saucepan over medium heat. Once the butter is melted start to whisk constantly. First the butter will begin to foam, then after a couple of minutes it will begin to brown on the bottom of the saucepan. Turn off the heat as soon as the solids turn brown and the butter gives off a nutty aroma.
Add the sugar to a medium bowl. Pour the brown butter over top being sure to scrape the bottom of the pot to get all the milk solids. Whisk to combine. Add the egg and vanilla then whisk until smooth.
Add the quick oats, flour and salt and mix with a spatula to combine. Drop the dough by teaspoonfuls on the prepared baking sheet, leaving about 2 1/2 inches between the cookies. You should be able to fit 12 to a baking sheet, but the cookies will spread so don't crowd them.
Bake for 12-14 minutes until the cookies start to turn golden brown. Remove the cookies from the oven and let cool on the pan for 2-3 minutes.
Use a small spatula to flip 6 of the cookies over on the baking sheet. Top the flipped cookies with 10-12 chocolate chips and let the heat of the pan melt the chocolate. If you find the chocolate isn't melting, place the cookie sheet back in the oven for 1 minute to help the chocolate melt. Spread the chocolate into a thin layer then top with a second cookie. Transfer to a cooling rack to cool completely.
Store the cookies in an airtight container or resealable bag at room temperature for up to 4 days. The cookies can be frozen in a resealable bag for up to 3 months. Enjoy!
Brown butter gives these cookies an extra delicious flavor. Brown butter gives these cookies a nutty aroma and flavor. You have to melt the butter anyway and browning it only takes 2 extra minutes. It is well worth the effort!
Use quick oats instead of rolled oats. Quick oats give these cookies a nice, even texture. Since rolled oats are larger they won’t make as delicate of a cookie.
Only use 1 teaspoon dough per cookie. Trust me when I say these cookies spread a lot! You’ll want to be sure to only use 1 teaspoon dough per cookie and to give the cookies plenty of space for spreading during baking.
Use a silpat baking liner. A nonstick silpat liner is very helpful for making these cookies. The cookies will easily come off a lined pan, but may stick to an unlined pan.
Melted chocolate will help hold these cookies together. Melted chocolate is not only delicious, it also solidifies as it cools and helps hold these cookies together. I recommend layering the lace cookies with chocolate if you’re planning on bringing them somewhere.