Pre-heat the oven to 180°C /160°C fan/gas mark 4.
Whisk the sorghum flour, tapioca flour and salt together in a medium bowl and set aside.
Stir the egg whites, sugar, vanilla together in a large bowl. Then whisk in half the flour mix.
Whisk in the melted butter, then the rest of the flour mix.
Rest the batter for 10 minutes.
Line a large baking sheet with greaseproof paper.
Drop 2 tablespoons of batter onto one half of the greaseproof paper and using an offset palette knife, swirl the batter into a circle of 12cm diameter.
Repeat to create another circle of batter on the other half of the greaseproof paper.
Bake these two cone discs for 8 minutes.
Remove the baking sheet and hold a palette knife in one hand and the cone mould in your other hand. Lift one of the pliable cone discs with the palette knife and shape it round the cone mould. Carefully place the cone into the cone holder to set its shape.
Repeat with the other cone disc.
Whilst the cones are cooling, make a second batch. Repeat the baking process until you have used up all the batter.
Once your cones are cool then fill with ice cream!