Prepare Your Pineapple: Peel, core, and slice fresh pineapple into 1/4 to 1/2-inch thick rings or half-moons, or drain canned pineapple rings. Pat the pineapple slices very dry with paper towels.

Whisk Dry Ingredients: In a large mixing bowl, combine all-purpose flour, granulated sugar, baking powder, and a small pinch of salt. Whisk together until evenly distributed.

Combine Wet Ingredients: In a separate bowl, lightly beat the egg, then whisk in the milk and vanilla extract if using. Mix until well combined.

Make the Batter: Pour the wet ingredients into the dry ingredients and stir gently until just combined. The batter should be thick but pourable.

Heat the Oil: Pour neutral oil into a heavy-bottomed pot or Dutch oven, about 2-3 inches deep, and heat over medium-high to 350-375°F (175-190°C).

Dip and Fry: Dip each dried pineapple slice into the batter, allowing excess to drip off, then gently lower into the hot oil. Fry 2-3 fritters at a time.

Cook Until Golden: Fry for about 2-4 minutes per side, or until golden brown and puffed up. Flip carefully with tongs or a slotted spoon.

Drain and Serve: Remove fritters from oil and place on a wire rack over a baking sheet lined with paper towels. Dust with powdered sugar while warm and serve hot.