In a large mixing bowl, combine tapioca starch, coconut flour, cinnamon, sea salt, and baking soda, and mix together.
Add coconut oil, maple syrup, egg, and vanilla extract. Stir together until a wet dough forms.
Scrape out the dough into a plastic wrap, form into a ball, and wrap. Chill for 10 minutes to firm up.
Remove the dough from the fridge and use a rolling pin to roll between 2 parchment paper into a rectangle about 9"x12" in size. The dough should be about 1/4 inch thick.
Remove the top parchment paper, and brush with 1 tbsp of coconut oil. Combine coconut sugar and cinnamon for the cinnamon filling in a small bowl and sprinkle evenly over the dough.
Use the bottom parchment paper, to lift up a shorter edge of the dough and start rolling as tightly as possible. Keep using the parchment paper to help with the rolling. It's okay to have cracks, just use your finger to smooth it out.
Transfer the rolled log onto cutting board, and loosely wrap with a plastic wrap. Chill for 15 minutes.
Preheat the oven to 350 degrees F, and line a baking sheet with parchment paper.
Remove the log from the fridge, and use a sharp knife to cut it into 1/2 inch slices. Wipe the knife between each slice.
Place the cookie slices on the lined baking sheet 1 inch apart. Bake for 9-11 minutes, until lightly browned at the edges. Cool completely before icing.
Make the icing by combining the ingredients in a bowl and microwaving for 10 seconds until thick and creamy like maple syrup, or use a double boiler to melt together.
Drizzle icing over the cookies.
You can serve right away, or allow the icing to cool and harden completely before storing in an airtight container for 4-5 days at room temperature, or up to 8-10 days in the fridge.