Lightly coat a 9" glass pie plate with coconut oil or butter.
In a small saucepan, heat the dairy-free milk until it reaches about 110°F. If it gets hotter, let it cool a few minutes so that you don't kill the yeast.
In a large mixing bowl, combine the melted butter, warm milk, and sugar. Gently stir in the yeast and let it set for 1 minute. Stir in 1 1/2 cups of cassava flour and shape the moist dough into a nice round.
Cover the mixing bowl with plastic wrap and place it in a warm location. I like to turn the light on in my oven and place a bowl of hot water in the oven along with my bowl of dough. Let the dough rest in the warm location for 30 minutes. It should get puffy and cracked.
While the dough is resting, make the cinnamon roll filling. Combine the softened butter, sugar, and cinnamon in a small mixing bowl. Stir until a soft paste forms.
After the dough has rested, uncover the bowl and add the remaining 1/2 cup of flour, sea salt, and baking soda. Stir until a soft, workable dough forms.
Cut a piece of parchment paper that is at least 15" long. Lightly flour the surface with about 1.5 tsp. of tapioca flour. Place the dough ball on the floured surface. Press the dough out into a rectangle that is 12 inches tall by 14 inches wide.
Spread the filling mixture evenly over the rectangle. Starting at the top of the rectangle, begin rolling one of the 12" sides towards you. I find it helpful to use the parchment paper to help roll up the dough.
Cut the roll into 8 pieces. Place each piece into the pie plate so that they are touching each other. Cover the pie plate with plastic wrap and let the cinnamon rolls rest in a warm location for 1 hour.
After 1 hour, remove the plastic wrap and preheat your oven to 325°F. Take the cinnamon rolls out of the oven while it preheats if you were letting them rest in the oven. Cover the pie plate with aluminum foil and bake for 40 minutes. Uncover the cinnamon rolls and bake for 10 more minutes or until the edges of the rolls are slightly firm to the touch.
Let the cinnamon rolls cool before storing them in an airtight container or serve them warm!