Combine flour, cinnamon and salt into a bowl and sift until well dispersed. Set aside.
2 ¾ cup all purpose flour, 1 ½ tsp ground cinnamon, 1 tsp fine sea salt
In a separate bowl, add butter, brown sugar and sugar and use mixer on medium to cream - about 2 minutes.
1 cup unsalted butter, softened, ½ cup light brown sugar, packed, ¼ cup sugar
Add dry ingredients to wet ingredients. Mix on low until most of the flour is combined, and then increase speed to combine ingredients well. Hot Tip! If the dough is crumbly, add 1 - 2 tablespoons of milk to help bring the dough together.
Use hands to knead the dough until it comes together.
Roll out dough until it's roughly 2" diameter. Hot Tip! For easier rolling, roll between 1 to 2 pieces of parchment paper.
Wrap dough in plastic wrap and refrigerate for at least 30 minutes.
Preheat oven to 350 F. Carefully use a sharp knife to slice cookies, about ½" thick.
Combine sugar and cinnamon in a separate bowl and sift thoroughly. Place cookie inside to coat both sides and edges.
Place 10 - 12 cookies per baking sheet. Bake for 14 - 15 minutes.
Remove from oven and allow to cool. Roll in cinnamon sugar for additional coating.