In a large mixing bowl, beat butter and brown sugar until light and fluffy.
Beat in egg, maple syrup, and maple extract.
In a medium bowl, whisk together flour, walnuts, baking powder, and salt.
Add the flour mixture to the mixing bowl, and beat until just combined.
Using a cookie press fitted with your choice of disk, press cookie dough 1-inch apart onto ungreased cookie sheets.
Sprinkle with sanding sugar or sprinkles.
Bake at 350 degrees for 8-10 minutes, or until bottoms are very pale brown.
Remove to wire racks to cool completely.