Preheat your oven to 350°F (175°C). Grease a 6-cup jumbo muffin pan or a standard 12-cup muffin pan.

Divide the melted butter evenly among the muffin cups. Sprinkle brown sugar over the butter in each cup.

Place a pineapple slice or piece in the bottom of each cup, then place a cherry in the center.

In a mixing bowl, beat together sugar and softened butter until creamy.

Add the egg and vanilla extract, and mix until well combined.

In a separate bowl, whisk together flour, baking powder, and salt.

Add the dry ingredients to the wet mixture alternately with milk, beginning and ending with flour mixture. Mix just until combined.

Spoon the batter over the pineapple in each muffin cup, filling about 3/4 full.

Bake for 20–25 minutes, or until a toothpick inserted in the center comes out clean.

Let the cakes cool in the pan for 5 minutes. Then run a knife around the edges and carefully invert onto a wire rack or tray to release the cakes.

Serve warm or at room temperature.