Mix yogurt and flour together, leave it on your counter overnight. If the mixture becomes too dry, you can always add more yogurt.
to 24 hours later, begin preparing the cake by heating the butter in a cast iron skillet until melted.
Add the sliced quinces to the butter and continue to cook until the quinces become slightly tender (they will NOT become fall-apart soft for this recipe).
Add ¼ cup sucanat or butter to the quinces.
As you cook the quinces, you’ll finish the batter by mixing in all remaining ingredients together until the batter becomes smooth.
Remove the quinces from the heat, and allow them to cool while you preheat the oven to 350 º F.
When the quinces have cooled slightly and the oven has been preheated, pour the batter over the quinces and place the skillet in the oven.
Bake the cake about 45 minutes or until a toothpick inserted into its middle comes out clean.
Serve directly from the skillet.