Start by cutting ½ cup of cold, cubed unsalted butter into a mixing bowl. Add ½ cup of light brown sugar, 1 cup of sifted all-purpose flour, 1 teaspoon of ground cinnamon, and a pinch of salt. Use a fork to blend until clumps form and refrigerate.

In a separate bowl, sift together 2 cups of all-purpose flour, 1 teaspoon of baking soda, 1 teaspoon of ground cinnamon, and ½ teaspoon of salt. Set aside.

In a large bowl, beat ½ cup of softened unsalted butter with ½ cup of granulated sugar and ½ cup of light brown sugar for 2-3 minutes until light and fluffy.

Add one large egg and one egg yolk, followed by 1 teaspoon of vanilla extract. Beat for about 2 minutes until well combined.

Gradually add the sifted dry mixture to the wet ingredients on low speed until just combined. Do not overmix.

Scoop the dough into balls and place them on a parchment-lined baking sheet, spaced 2 inches apart. Make a gentle indent in each ball.

Cover the baking sheet with plastic wrap and refrigerate the dough for at least 1-2 hours.

Preheat the oven to 350°F (175°C) and bake the chilled cookies for 13-15 minutes until edges are set and centers slightly soft. Cool on a wire rack.

In a small bowl, whisk together 1 cup of sifted powdered sugar, 2 tablespoons of whole milk, and ½ teaspoon of vanilla extract until smooth. Drizzle over cooled cookies and let set for 10-15 minutes.