To brown the butter, melt it in a small saucepan over medium heat. Cook until the butter melts and begins to brown, about 3-4 minutes. You'll know it's done when it turns a deep amber color and starts to smell nutty. Remove from the heat and transfer to a bowl to cool slightly.
1 cup unsalted butter
Whisk the flour, baking soda and salt together in a medium bowl and set aside.
2 1/2 cups all purpose flour, 1 teaspoon baking soda, 1/2 teaspoon salt
Using a hand mixer or a stand mixer fitted with the paddle attachment, beat the brown butter and sugar on high speed until light and creamy, 2-3 minutes. Add the maple syrup, maple extract, vanilla extract, milk, and eggs and beat on high for another 2-3 minutes.
1 cup light brown sugar, 1/4 cup pure maple syrup, 1 teaspoon maple extract, 1 teaspoon vanilla extract, 1 Tablespoon milk, 2 large eggs
Slowly add half of the dry ingredients to the wet mixture and turn the mixer on low to start so the flour doesn't get everywhere. Turn the mixer up to high and mix until combined. Add the rest of the dry ingredients and repeat until dough is just combined. Add the pecans and stir with a rubber spatula until incorporated.
1 cup chopped pecans
Cover the dough with plastic wrap and chill in the fridge for at least 2 hours, or up to 3 days.
When you're ready to bake, preheat the oven to 350°F. Line a large baking sheet with parchment paper.
Use a large cookie scoop (about 3 Tablespoons) to scoop out the dough. Drop them a few inches apart on the prepared baking hseet. Bake for 10-12 minutes, until just set on top and the edges are golden. Cool for 5 minutes on the cookie sheet then transfer to a wire rack.
While they're cooling, make the icing. Melt the butter in a medium microwave safe bowl in the microwave for 15-30 seconds. Whisk in the maple syrup then whisk in the powdered sugar until smooth. Place a piece of parchment paper under the cookies on the wire rack and drizzle the cookies with the icing. It will set as it cools.
2 Tablespoons unsalted butter, 1/4 cup maple syrup, 1 cup powdered sugar