Pre heat your oven to 350 degrees and line your baking sheets with parchment paper.
In a sauce pan over medium high heat, add your butter and let melt. Once it's melted keep it on the heat and let it cook for 5-10 minutes until it foams up and then turns brown. Let cool.
In a large bowl add your browned butter, brown sugar and 1/3 cup of white sugar and whisk until combined.
Add your eggs and vanilla extract and whisk again. Whisk until your mixture is very light and fluffy and is almost foamy.
Next, add your in your dry ingredients and spices. Your flour, cornstarch, salt, baking soda, cream of tartar, 1 tbsp cinnamon, nutmeg and ginger. Fold until everything is just combined.
In a small bowl add your remaining 1/3 cup of sugar, 2 tablespoons of cinnamon and whisk together.
Scoop out your cookie dough into 1-2 inch balls, roll in cinnamon sugar and place on your baking sheets lined with parchment paper a few inches apart.
Bake at 350° for 8-10 minutes. Remove from oven when golden brown.
Top with flaky sea salt, extra cinnamon sugar, let cool, and enjoy!!