By Sarah Murphy-Kangas, In Praise Of Leftovers
Chilling the dough is recommended. It’s quite soft and you might have trouble with the cookies spreading if you don’t.
3 cups all-purpose flour
1 teaspoon kosher salt
1 cup (2 sticks) unsalted butter, room temperature
1 cup sugar
1 cup pure maple syrup
2 large egg yolks
12-ounces walnut halves
Fleur de sel or other coarse salt, for sprinkling
1. Preheat oven to 350 degrees F. In a medium bowl, whisk together flour and kosher salt. In the bowl of an electric mixer fitted with a paddle, cream together butter and sugar until light and fluffy. Scrape down the sides of the bowl, add 1/2 cup of the maple syrup and the egg yolks, and beat until fully incorporated. Add the flour mixture and mix until just combined. Chill dough for 30-60 minutes.
2. Using a tablespoon, drop dough, 3 inches apart, onto two baking sheets. Using your thumb, make an indentation in the center of each round of dough – as deep as you can go without pushing through. Bake until the edges are just golden, 12-15 minutes. Transfer to a wire rack and cool.
3. While the cookies are cooking, prepare the maple glaze. Place the remaining 1/2 cup maple syrup in a small saucepan over medium heat. Simmer the syrup until reduced to abut 1/3 cup, 7-10 minutes. Carefully spoon the glaze into the thumbprint of each cooled cookie, then place a walnut and a sprinkle of salt on top. Allow the glaze the set, at least 10 minutes, before serving.