Whisk together the dry ingredients in a small bowl. Set aside.
In a medium bowl, whip your butter with a hand mixer (or stand mixer) until it's lighter in color.
Add the allulose. Cream together the butter and allulose until it is a very pale color.
Mix in eggs. Mixture may appear "broken" at this stage. This is fine.
Add the dry ingredients into the wet. Mix together well, ensuring all the powder is fully combined. The dough will be somewhat sticky.
Refrigerate dough for about 15 minutes.
Preheat oven to 350°F. Mix the remaining erythritol and cinnamon together in a shallow bowl.
Using a cookie scoop (or a spoon), create uniform cookies.
Roll each cookie in the erythritol/cinnamon mixture until fully coated.
Place evenly on a parchment lined cookie sheet. Don't overcrowd the pan.
Bake cookies for 9-12 minutes or until the cookies are set and beginning to brown on the bottom (11 minutes is perfect in my oven).
Remove pan from oven and allow it to "drop" on your counter to flatten the cookies.
Allow cookies to cool for about 10 minutes on the pan and then move them to a cooling rack.
Cool completely before storing in an airtight container.