Preheat oven to 400°. Line a large baking sheet with parchment paper and set aside.
In a large bowl, combine the dry ingredients: all purpose flour, cake flour, corn starch, cinnamon, baking soda, baking powder and salt. Set Aside.
Add cubed butter and both sugars into the bowl of a stand mixer, using paddle attachment, or a hand held mixer. Cream butter and sugars together until nice and smooth, about 2 minutes.
Add in the egg, egg yolk and vanilla. Blend until mixed.
Gradually add in the dry ingredients. Mix until incorporated.
Using a large cookie scoop, scoop 8 large balls of dough and place on baking sheet.
Make an indent in each cookie using the back of cookie scoop.
Spoon in 1 tbsp of the streusel and fill in each cookie.
Bake for 9 to 11 minutes, or until edges appear set and are slightly golden brown. (They will seem super soft, but you don't want to over bake them. They will continue to bake when they are out of the oven and resting.)
Let the cookies cool completely on a cooling rack.
Mix together ingredients for icing once the cookies are cooled, and drizzle each cookie. Enjoy!!!