Preheat oven to 400 degrees Fahrenheit (200 degrees Celsius).

Line up small round kugelette tins on a tray or two ready to be filled. Spray bottoms with cooking spray if desired.

Peel sweet potatoes and cut into large cubes. Process together with half the onion, using the knife attachment of the food processor, pulsing until small pieces are formed. You don’t want it to mush. Transfer to a large mixing bowl. Add three to four eggs, salt and pepper, and half a tablespoon of baking powder.

Preheat one quarter cup of oil in the oven and pour into sweet potato mixture. Mix everything together well. Pour one quarter cup of mixture into each tin, using a one quarter-cup measuring cup. Tap lightly on the counter so it’s level. Place in oven and bake for 25 minutes or until slightly crispy on top.

Meanwhile, prepare potato layer: Peel potatoes and process together with onion, as above. Drain well in strainer, pressing down on potatoes and onion to release all extra liquid. Transfer to a large bowl and following directions above. Return tins to oven and continue baking for 30 minutes or until very crispy and brown on top. Remove from oven and cool to room temperature.