Preheat the oven to 350 F. Line several cookie sheets with parchment paper.
Beat butter, shortening and sugars together until fluffy, about 2-3 minutes.
Add the egg and vanilla extract and mix well.
In a medium bowl, combine flour, cinnamon, baking powder, baking soda and salt.
Add dry ingredients to wet ingredients and mix until just combined.
Using a medium (1-½"D) cookie scoop, scoop dough onto prepared baking sheets. Make an indent in the center of the cookies and over-fill with crumb topping (see instructions below).
Bake for 10-12 minutes or until just set.
Let cool on cookie sheet for 5 minutes then move to a wire rack to cool slightly.
When cool, drizzle the cookies with vanilla icing then dust with a little powdered sugar.
Crumb Topping
Mix all ingredients in a small bowl, stirring with a fork or pinching with fingers, until it resembles coarse crumbs. DO NOT OVERMIX SO IT LOOKS LIKE PASTE!
Vanilla Icing
While the cookies are baking, make the icing.
Beat all ingredients together until smooth. You can use a mixer or easily do it by hand. If it looks too thick to drizzle add more milk, if too thin add a little more powdered sugar.
Notes
STORE/FREEZEStore at room temperature in an airtight container for 4-6 days.Freeze separately on a cookie sheet then place frozen cookies with parchment paper in between layers in a resealable freezer container or bag together. They will keep for 3 months. Thaw at room temperature when ready to eat.