How to Make It
In a small saucepan, combine 2 tablespoons of the sugar with 2 tablespoons of water and simmer the syrup over moderate heat just until the sugar has dissolved.
In another small saucepan, combine the remaining 1 cup of sugar with 1⁄2 cup of water and simmer over moderate heat, without stirring, until an amber caramel forms (340° on a candy thermometer), about 15 minutes. Immediately add 1/3 cup of water and the sugar syrup; be careful, as the caramel mixture will bubble and splatter. Whisk until smooth, then transfer the caramel syrup to a medium bowl and let stand for 30 minutes.
In a large, heavy saucepan, heat the canola oil until just smoking. Add the popping corn, cover and cook over moderately high heat, shaking the pan constantly, until the kernels have stopped popping, 2 to 3 minutes.
In another large saucepan, combine the popcorn with the salt, butter, sugar and 31⁄2 cups of water. Bring to a simmer and cook over moderate heat for 5 minutes. Strain the broth through a fine sieve into a bowl, pressing on the popcorn until only the kernels remain; discard the kernels.
Transfer the popcorn broth to a blender and blend until frothy, about 3 minutes. Add the lecithin powder to the caramel syrup and blend with an immersion blender until frothy.
Pour the warm popcorn broth into small glasses, filling them halfway (about 1⁄4 cup each). Spoon some of the caramel froth on top and serve.
Soy lecithin powder is available at health-food stores and online at amazon.com.