You can easily substitute the tigernut flour for all-purpose if that is what you have on hand.
2 Tablespoons sugar
1 Tablespoon brown sugar
2/3 coconut yogurt (regular full-fat yogurt is ok too)
1 cup olive oil + 1 Tablespoon for greasing the cast iron
1 cup fine cornmeal
1 cup tigernut flour
1 teaspoon salt
2 teaspoons baking powder
In a medium bowl whisk the eggs and sugars together. Add the yogurt, whisk, then add the oil in a steady stream while whisking.
Sprinkle the corn flour evenly over the top. Sprinkle the tigernut flour evenly over the top. Sprinkle the salt and baking powder evenly over the top. Gently whisk everything together until the moment it becomes smooth.
Grease an 10" cast iron with 1 Tablespoon of olive oil and pour the batter in. Bake in the oven until the cake is set in the middle, golden on top, and the edges a little dark— about 30 minutes.