Dissolve gelatin in 6 tablespoons of boiling water.
Add vanilla, syrup, and sea salt.
Beat with electric mixer for 12 minutes, until marshmallows are thick. Should triple in size.
Coat 9×12 dish with coconut oil and dust with starch. Pour marshmallows into dish.
Let cool for at least 3 hours, or overnight.
Cut marshmallows into squares with wet knife.