Make the Streusel: In a medium bowl, whisk together flour, brown sugar, granulated sugar, cinnamon, and salt. Stir in the melted butter and vanilla until crumbly and incorporated. Set aside.
1/2 cup + 2 Tbsp all-purpose flour, 1/4 cup light brown sugar, 2 Tbsp granulated sugar, 1 tsp ground cinnamon, 1/8 tsp salt, 1/4 cup unsalted butter, splash of vanilla
Make the Cookie Dough:(a) Using the bowl of a stand mixer fitted with the paddle attachment, cream together the butter, granulated sugar, and brown sugar until light and fluffy (2-3 minutes). Scrape down the sides of the bowl as needed.(b) Add the egg, egg yolk, milk, and vanilla. Mix until smooth. Once again, scrape down the sides of the bowl if needed.(c) In a separate bowl, whisk together the flour, baking powder, cinnamon, cornstarch, salt, and baking soda.(d) Gradually add the dry ingredients to the wet ingredients, mixing just until combined. 1 cup unsalted butter, 1 ¼ cups granulated sugar, 1/4 cup dark brown sugar, 1 large egg, 1 large egg yolk, 1 Tbsp whole milk, 2 tsp vanilla extract, 2 ¾ cups all-purpose flour, 1 ½ tsp baking powder, 1 tsp ground cinnamon, 1 tsp cornstarch, 3/4 tsp salt, 1/2 tsp baking soda
Scoop & Fill: Scoop dough into 2 Tbsp-sized portions (you’ll get about 18-20 cookies). Roll into balls and place on a parchment-lined plate or small baking sheet. Using the back of a tablespoon (lightly dipped in flour), press an indent into the center of each cookie. Fill each indent with streusel, ~2-3 tsp.
Chill: Chill the filled cookies for 30-60 minutes. (Make sure you have room in the fridge for your tray or use a parchment-lined plate.)
Bake: Preheat oven to 350°F. Place cookies on a parchment-lined baking sheet, spacing a few inches apart (I bake 6-8 at a time) Bake for ~10 minutes, or until edges are set and centers look just slightly underbaked. (Do not over bake them, they’ll set more as they cool). Immediately upon removing from the oven, use a round glass or biscuit cutter to gently “scoot” the cookies into perfect circles. Cool on the baking sheet for a few minutes, then transfer to a wire rack.
Glaze: Whisk together powdered sugar, milk, salt, and vanilla until smooth. Adding a little more powdered sugar or milk to get the perfect consistency. Drizzle over cooled cookies. ENJOYY!!
1 cup powdered sugar, 2 Tbsp milk, Pinch salt, 1/2 tsp vanilla