Preheat the oven to 350°F (175°C). Line a baking sheet with parchment paper.

In a large bowl, beat together the sugar, water, and margarine until light and smooth.

Mix in the egg, vanilla, and nutmeg until combined.

In a separate bowl, whisk together the cassava flour and baking powder.

Add the dry ingredients to the wet mixture and mix until a soft dough forms. Chill the dough for at least 30 minutes.

Drop spoonfuls of the chilled dough onto the prepared baking sheet, spacing them about 2 inches apart.

Bake for about 10 minutes, until the edges are set and the bottoms feel firm. The cookies will still look pale. Do not wait for them to turn golden or they can become dry.

Let the cookies cool on the baking sheet for a few minutes before transferring them to a cooling rack. They will continue to firm up as they cool.