Prep the pan: Preheat your oven to 350°F (175°C). Generously grease a 10- to 12-cup Bundt pan with butter and dust with flour, or use baking spray with flour. Make sure every ridge is coated.

Make the caramel layer: Melt 1/2 cup butter in a small saucepan over medium heat. Stir in 1 cup brown sugar until smooth and glossy, about 1–2 minutes. Pour this mixture evenly into the bottom of the Bundt pan.

Arrange the fruit: Pat pineapple rings dry. Lay them on top of the caramel in a single layer, tucking in as many as will fit without overlapping too much. Place a maraschino cherry in the center of each ring and nestle extras in gaps if you like.

Dry ingredients: In a medium bowl, whisk together 2 cups flour, 2 teaspoons baking powder, 1/2 teaspoon baking soda, and 1/2 teaspoon salt.

Wet ingredients: In a large bowl, beat 1/2 cup softened butter with 1 cup sugar until light and fluffy, 2–3 minutes. Add 3 eggs one at a time, mixing well after each. Stir in 2 teaspoons vanilla, 1/2 cup sour cream, 1/4 cup oil, 1/2 cup milk, and 1/4 cup pineapple juice.

Combine: Add the dry ingredients to the wet in two additions. Mix on low just until no dry streaks remain. The batter should be thick but pourable.

Fill the pan: Spoon the batter over the pineapple layer. Spread gently to the edges to avoid dislodging the fruit.

Bake: Place the pan on a baking sheet to catch any potential drips. Bake for 45–55 minutes, or until a toothpick inserted into the cake (not the fruit layer) comes out clean and the top feels springy.

Cool briefly: Let the cake rest in the pan for 10–15 minutes. This helps the caramel set slightly while still being loose enough to release.

Invert and reveal: Run a thin knife around the edges and center tube. Place a serving plate on top of the pan, grip both firmly with oven mitts, and flip in one confident motion. Lift the pan to reveal the glossy pineapple top.

Serve: Cool another 20 minutes before slicing. Serve warm or at room temperature. Add whipped cream or vanilla ice cream if you like.