Prep the pan: Heat the oven to 350°F (175°C). Grease a 9-inch round cake pan (2 inches deep) or a 10-inch cast-iron skillet. Line the bottom with parchment for easy release.

Make the caramel topping: In a small saucepan, melt 1/2 cup butter over medium heat. Stir in the brown sugar and cook 1–2 minutes until glossy and bubbling. Pour into the prepared pan and tilt to coat the bottom evenly.

Arrange the fruit: Lay pineapple rings over the caramel, fitting as many as you can in a single layer. Place a cherry in the center of each ring and in any gaps. Patting the fruit dry helps the cake set neatly.

Mix dry ingredients: In a medium bowl, whisk flour, baking powder, baking soda, and salt. Set aside.

Cream butter and sugar: In a large bowl, beat softened butter and granulated sugar until light and fluffy, about 2–3 minutes. This step gives you a tender crumb.

Add eggs and vanilla: Beat in eggs one at a time, scraping the bowl. Mix in the vanilla.

Combine wet ingredients: In a small bowl or measuring cup, whisk sour cream, milk, and pineapple juice until smooth.

Finish the batter: Add the dry ingredients to the butter mixture in two additions, alternating with the sour cream mixture. Start and end with dry. Mix just until combined; don’t overmix.

Assemble: Gently spoon the batter over the pineapple layer and smooth the top. The batter will be fairly thick.

Bake: Bake 35–45 minutes, until the top is golden and a toothpick inserted in the center comes out mostly clean with a few moist crumbs.

Cool and invert: Let the cake rest on a rack for 10–15 minutes. Run a thin knife around the edges. Place a serving plate over the pan and carefully flip. Lift off the pan and peel away the parchment.

Serve: Let the cake set 10 minutes before slicing. Serve warm, with ice cream if you like.