Measure half baking sheet with parchment paper and cut parchment paper to fit (leave 2 inches of extra space on all four edges). Place baking sheet (without parchment paper) in the oven and preheat oven to 425 degrees Fahrenheit.
While oven is preheating and baking sheet is heating up, place cassava flour, arrowroot starch, 1 tsp fine sea salt, 1 tsp cracked rosemary, and onion powder in large bowl and mix well.
In separate bowl, add all liquid ingredients and mix with whisk.
Pour liquid mixture into dry mix and mix well until fully incorporated. Let rest for 5-10 minutes.
Place parchment paper on large cutting board and pour batter onto parchment paper. Cover with plastic wrap and gently roll out to desired shape (leave 2 inches of space on all 4 edges). Then, remove and discard plastic wrap. (You can also avoid using plastic wrap and just spread out batter with wet spatula or oiled fingers.)
Sprinkle remaining 1 tsp cracked rosemary and 1/2 tsp coarse sea salt over top evenly.
When oven is preheated, remove baking sheet and carefully place parchment paper with batter no baking sheet. Then, return to oven for 20 minutes or until crispy on outside and soft on inside.
Let cool slightly, then slice and enjoy!
This recipe is a similar recipe to my pizza crust. The difference is the seasoning and the thickness of the batter.