In a small bowl, dissolve the yeast in 1 cup of warm water along with 1 teaspoon of sugar. The water should be warm, approximately between 110°F to 115°F (43°C to 46°C), which is comfortably warm to the touch but not hot. This temperature range is optimal for activating yeast without killing it. Let it sit for about 5 minutes until it becomes frothy.
In a large mixing bowl, combine the flour, sugar, salt, and any optional flavorings like nutmeg or cinnamon.
Make a well in the center of the dry ingredients and pour in the yeast mixture. Stir everything together until you get a thick, smooth batter. The batter should be thick enough to hold its shape but still soft and pliable.
Cover the bowl with a clean kitchen towel or plastic wrap and let the batter rise in a warm place for about 1-2 hours, or until it doubles in size. This step allows the yeast to ferment and create air bubbles, giving the puff puff its characteristic fluffy texture.
Once the batter has risen, heat the vegetable oil in a deep frying pan or pot over medium heat. You want enough oil to submerge the puff puff completely while frying but without overcrowding the pot. A depth of about 2-3 inches (5-8 cm) of oil in the pot should be sufficient. The oil should be hot enough to fry the puff puff but not too hot that it burns them quickly.
Using a spoon or your hands, scoop up small portions of the batter and carefully drop them into the hot oil. For beginners, I recommend using a spoon that you've greased with oil. This prevents the dough from sticking to the spoon, and allows you to get that round shape. You can shape them into balls or any desired shape. Make sure not to overcrowd the pan, as the puff puff will expand as they fry.
Fry the puff puff in batches, turning them occasionally with a slotted spoon to ensure even cooking. They should puff up and turn golden brown in about 3-5 minutes.
Once cooked, remove the puff puff from the oil and drain them on paper towels to remove any excess oil.
Serve the puff puff warm as a snack or dessert. They can be enjoyed plain or dusted with powdered sugar for added sweetness.