Combine powder, water, and salt in a saucepan, mixing well to dissolve.
Heat pot over medium, stirring occasionally, until bits of gelatin begin to form and the liquid thicken.
Continue coking, stirring constantly until it becomes thick enough to form peaks that hold their shape.
Add oil, stirring to incorporate. Continue cooking until acorn is fully cooked.
Transfer mixture to a shallow mold, shaking to distribute evenly. Loosely cover and cool until set.