Preheat the oven to 350°F. Line 2-3 baking sheets with parchment paper and set aside.
In a small saucepan over medium-low heat, melt the butter with the brown sugar and maple syrup, stirring consistently until fully melted. Remove from heat and stir in the oats, flour, and salt. Allow mixture to sit for 5 minutes to thicken.
½ cup (113g) unsalted butter, ⅔ cup (134g) light brown sugar, 2 tablespoons pure maple syrup, 1 cup (90g) quick cooking rolled oats, ¼ cup (38g) gluten free flour blend*, ¼ teaspoon fine sea salt
Drop teaspoonfuls of the mixture onto the lined baking sheet, keeping them several inches apart. Bake for 7-8 minutes, or until golden brown. Remove and allow cookies to cool on baking sheet for 5 minutes before transferring to a cooling rack.
Once the cookies are completely cooled, gently spread melted chocolate on one side of half of the cookies. Top each one with another cookie, creating a sandwich cookie. Allow to set in the refrigerator about 10 minutes before serving.
8 ounces chocolate
Notes
If you are not following a gluten free diet, feel free to use all-purpose flour here. No need to adjust the measurement.
These cookies are thin and crispy. They will spread considerably, so it's important to not place them too close together on the baking sheets. I tend to fit about 6 teaspoonfuls per baking sheet, and bake them in batches that way.