In a large bowl with an electric mixer, beat butter until smooth.
Add sugar, brown sugar and maple syrup and beat until light and creamy, about 2-3 minutes.
Add egg and beat until combined.
Add baking soda, cream of tartar, vanilla and salt and beat on low speed just until combined.
Add flour and beat on low speed until a dough comes together.
Roll into 1" balls and place on baking sheets (I like to line mine with parchment paper). Bake for 8-9 minutes, until tops appear dry and puffed and edges may be slightly golden.
Let cool for 5 minutes before removing from the pan to cool completely.
Maple Glaze
Whisk together powdered sugar and maple syrup, one tablespoon at a time, just until it reaches a drizzling consistency. You want it thick so that the glaze sets completely and doesn't stay sticky.