We start with the wet ingredients and sugar. In a large mixing bowl, cream together 1 cup of melted and cooled brown butter (reserving the rest for the apple cider glaze) and 1 & ¼ cups of dark brown sugar for 8 to 10 minutes until very light in fluffy in color.
Add in ½ cup of the cooled apple cider reduction (reserving the rest for later), along with 1 tablespoon of vanilla extract, and cream together for another 1-2 minutes until smooth, then add the egg and the egg yolk and cream together until just combined.
Now for the dry ingredients. Sift in 3.5 cups of flour, 1 tablespoon of cinnamon, 1 teaspoon of baking soda, and 1 teaspoon of kosher salt. Use a hand mixer on medium speed to combine the ingredients. Then, switch to a rubber spatula to finish to avoid over-mixing.
Allow the cookie dough to chill in the fridge (covered) for at least two hours but up to overnight. When it's time to bake and the cookies have chilled, preheat the oven to 350°F and line a large baking sheet with parchment paper.
In a small bowl, mix together ½ cup of white sugar with 2-3 teaspoons (to taste) of ground cinnamon to make the cinnamon sugar. Set aside.
Roll the cookie dough 12 to 16 large balls of dough using a number 20 cookie scoop. Scoop the cookie dough using the cookie scoop then use your hands to form a round shape and roll the cookie dough in the cinnamon sugar mixture until very well coated. Place the cookie dough on the prepared baking sheet. Pro tip. Make sure you leave plenty of room on the baking sheet for the cookies to spread. We recommend adding only about 4 to 5 cookies per baking sheet.
Bake for 12 to 15 minutes until the edges are set and the cookie looks slightly underdone in the middle. Allow the cookies to cool on the cookie sheet for a few minutes then transfer them to a cooling rack to cool completely.