First, let's make the grain free cinnamon spiced cookies. Preheat your oven to 350. First, add the butter and both sugars to a bowl (or to a mixer if you would like, but keep it on low speed during the whole process) and begin to cream together the butter into the sugar until creamy.
Next, add in the egg yolks and vanilla extract and mix well, again until creamy and smooth.
Next, add in the flour, remaining dry ingredients, and mix until the dough comes together.
Line a cookie sheet with parchment paper. Using a big cookie scoop (3 tbsp), scoop out the dough and place on the cookie sheet, leaving a good amount of space in between each cookie. I do 5-6 at a time. Bake for 13-14 minutes, rotating your cookie sheet at the halfway point to ensure even baking for all of the cookies.
While the cookies are baking, let's make the frosting. Add your butter to a bowl or mixer on low, and cream the butter until smooth.
Add in the powdered sugar and cream together until the frosting is smooth.
Divide the frosting in ½ and to one ½, add in the cinnamon.
Let's start on creating the frosting swirl. Lay down a sheet of saran paper, and in a vertical pattern, spread the plain frosting onto the saran wrap. Then, do the same thing with the cinnamon flavored frosting as seen below.
Tightly, but gently roll up the saran wrap, twisting the ends shut. Cut one end off and place that in a piping bag fitted with your preferred piping tip. I used a Wilton 12 round tip. Set the frosting aside or store in the fridge until ready to use. Once the cookies are cooled completely, pipe on a generous amount of frosting. You should get a nice swirled look to it for that quintessential cinnamon roll look.