Preheat oven to 350F degrees. Line two large baking sheets with parchment paper or silicone baking mats. Set aside.
Whisk together the flour, baking soda, and baking powder in a medium size bowl. Set aside.
In a large bowl, using an electric or stand mixer, cream together the butter, and granulated sugar until combined.
Add egg yolks, vanilla extract and maple syrup.
Add flour mixture and mix until just combined. DO NOT OVERMIX!
Using a cookie scoop or ice cream scoop, scoop dough into balls about 2 Tablespoons each, roll in sugar and place onto prepared baking sheet.
Bake for 15-18 minutes or until tops of cookies start to crack. Let cool for 5 minutes on baking sheet before moving them to a wire rack. Let cool completely on wire rack.
Make Maple Icing:
In a medium bowl, stir together melted butter, heavy cream and maple syrup. Gradually stir in powdered sugar until smooth. Drizzle on top of cooled cookies.