In a large bowl sift and stir together powdered sugar and cornstarch.
Lightly spray a 8x8 inch or 9x9 inch square baking pan with non-stick spray. Next, line the pan with parchment paper that hangs over all 4 sides but lays flat across the bottom of pan.
Lightly spray parchment paper with non-stick baking spray.
Then sift powdered sugar/cornstarch to create a think coating across sided and bottom of pan.
In the bowl of a stand mixer, stir together water and gelatin. The gelatin will absorb and "bloom". Meanwhile make sugar syrup.
Sugar Syrup Mix
Combine sugar, water, and corn syrup in a medium saucepan on stovetop and heat on low until sugar has dissolved.
Increase the heat a boil and cook for 6–7 minutes, checking the temperature to reach 240 F ( 115 C )on a sugar (candy) thermometer.
Turn on stand mixer fitted with whisk attachment to high speed. Then very carefully and slowly pour hot sugar syrup into the gelatin mixture.
Continue to whip on high for 8-10 minutes until tripled in size, thick and fluffy.
Sunflower Butter Swirl
In a small bowl stir together Creamy SunButter with vanilla and cinnamon.
Use a fork and gently add streaks and small chunks of the sunflower mixture into the fluffy marshmallow. Use a rubber spatula to fold in the streaks.
Transfer swirled marshmallow into prepared pan with rubber spatula and level.
Generously sift powdered sugar/cornstarch to create a think blanket over the marshmallow cream.
Let sit uncovered in a cool dry place for 4 hrs to dry out and set or overnight.
Lift marshmallow square from pan by grabbing the overhanging parchment paper.
Flip the marshmallow out onto a cutting surface lightly dusted with powdered sugar/cornstarch mixture. Dust a sharp knife and cut into squares. Coat the marshmallows with more sugar mixture and dip the sides if you like.