In bowl mix flour, salt, baking powder and nutmeg. Set aside. In separate bowl mix butter and brown sugar until fluffy, scraping sides down. Mix in maple syrup, once mixed well add egg and vanilla and continue to mix, scraping sides. Mix in dry ingredients on low until everything just comes together. Form into a ball and chill in fridge for at least 2 hours or over night.
Once chilled, preheat oven to 375 degrees. Roll out dough to 1/4 inch thick and using cookie cutter, cut out shapes. Place parchment paper or liner on cookie sheet and place cut out cookies on the cookie sheet, 1 inch apart. Bake in 375 degree oven for 7-9 minutes, or until golden brown colour. Cool on cookie sheet for 5 minutes and then transfer to cooling rack. Once cooled arrange cookies according to size and frost the bottom cookie, lying the other cookie on top.
2 tbsp butter
2 tbsp maple syrup
2 cups icing (powdered) sugar
1/4 cup milk
Whip butter until soft, add about 1/2 cup icing sugar and continue to whip. Add maple syrup and milk. Add icing sugar until the frosting becomes stiff but spreadable. You may have to add more icing sugar or milk to make it spreadable without being watery.