Step 1: Prepare the Pineapple

1. If using a fresh pineapple, peel it and slice it into 1/2-inch thick rings. Remove the core using a knife or corer.
2. If using canned pineapple rings, drain them well and pat them dry with a paper towel to remove excess moisture.

Step 2: Make the Batter

1. In a mixing bowl, combine the flour, cornstarch, baking powder, and salt.
2. Gradually add cold water and whisk until you get a smooth, thick batter. If you prefer a crispier texture, add an egg to the batter and mix well.

Step 3: Coat the Pineapple Rings

1. Dip each pineapple ring into the batter, ensuring it’s fully coated.
2. Roll the battered ring in breadcrumbs (or a mix of breadcrumbs and shredded coconut) until evenly coated.

Step 4: Heat the Oil

1. In a deep frying pan or skillet, heat the vegetable oil over medium heat.
2. To check if the oil is ready, drop a small amount of batter into the oil. If it sizzles and rises to the surface, the oil is hot enough.

Step 5: Fry the Pineapple Rings

1. Carefully place the coated pineapple rings into the hot oil, one at a time.
2. Fry for 2-3 minutes on each side, or until golden brown and crispy.
3. Use a slotted spoon to remove the rings from the oil and place them on paper towels to drain excess oil.