Preheat your oven to 350°F (177°C). Line two baking sheets with parchment paper.

In a medium bowl, whisk together all-purpose flour, baking powder, and salt; set aside.

In a stand mixer, cream unsalted butter and granulated sugar until light and fluffy, about 3 minutes. Beat in the egg and vanilla until glossy.

Stir in the flour mixture until just combined, then gently fold in the drained crushed pineapple. Chill the dough for 30 minutes.

Scoop 2-tablespoon portions of dough and roll into balls. Place 12 on each prepared sheet, spacing 2 inches apart.

Press a halved pineapple ring onto each cookie and top with a halved maraschino cherry.

Bake for 12–14 minutes, until edges are lightly golden and the topping bubbles.

Let cookies cool on the pan for 5 minutes before transferring to a wire rack to cool completely.