Whisk the flour, baking soda, and salt together in a medium bowl. Set aside.

Using a hand mixer or a stand mixer fitted with a paddle attachment, combine the butter and brown sugar together on medium speed until smooth and creamy, at least 1-2 minutes.

Add the egg and beat on high until combined, about 30 seconds. Scrape down the sides and bottom of the bowl as needed. Add the maple syrup, vanilla extract, then beat on high speed until combined.

Add the dry ingredients to the wet ingredients, then mix on low until combined. Add the nuts if using. Dough will be creamy and soft.

Cover and chill the dough for 2 hours in the refrigerator (or overnight). 

Preheat oven to 350°F.  Line 2 large baking sheets with parchment paper or silicone baking mats. 

Roll cookie dough into balls, about 1.5 Tablespoons of dough per cookie (if dough is too hard from coming out of refrigerator, let it come to room temperature). Bake each batch for 12-13 minutes until lightly browned on the sides. The centers will look very soft.

Remove from the oven. Gently tap the pan on the counter when you remove it from the oven to deflate the cookies. Cool cookies on the baking sheets for 5 minutes before transferring to a wire rack to cool completely.

Make the icing: In a small saucepan over low heat, melt the butter and maple syrup together, whisking occasionally. Once the butter has melted, remove from heat and whisk in the sifted confectioners’ sugar. Taste. Add a pinch of salt, if desired. Drizzle over cooled cookies and top with Maple Sprinkles if desired.

Cookies stay fresh covered at room temperature for up to 1 week. Makes about 2 dozen cookies.