In a saucepan over medium heat, melt butter then turn off heat and let it cool down to room temperature.
In a large bowl, mix flour, baking soda, baking powder, salt and cream of tartar until everything is well combined.
In your food processor, add melted and cooled butter, eggs, vanilla extract and all sugars. Pulse until well combined.
Add the dry ingredients and pulse again until you have a consistent dough, be sure to scrape sides and bottom.
Work the dough with your hands a bit until you are sure the dough is consistent.
Wrap the dough with plastic wrap and refrigerate for a couple of hours.
Preheat oven to 350F.
Line two large baking sheet with parchment paper or silicone baking mats.
Combine coating mixture in a small bowl and set aside.
Take 1 1/2 tablespoon of cookie dough and form into a ball. Roll into the cinnamon sugar mixture.
Place balls on the baking sheet and bake until lightly browned on the edges.Cookies will look as if they are not done yet at the center and be extremely soft.***
Remove from oven and let it cool for a couple of minutes on the baking sheet. Transfer to a cooling rack to cool completely.