Preheat your oven to 350℉. Grease a 9-inch cake pan or pie plate well with butter to ensure the cake comes out easily.
In a small bowl, combine ¼ cup melted butter with ½ cup brown sugar using a fork. You want to mix until well combined. This mixture will form a sweet, gooey base in your cake pan.
Spread the butter-sugar mixture evenly over the bottom of the prepared cake pan. It should cover the base nicely.
Now, arrange 7 pineapple rings in a single layer over the sugar mixture. If you have extra pineapple rings, feel free to cut them and arrange around the edges. Nestle 10 maraschino cherries inside the pineapple rings and anywhere else for an extra burst of color.
In a medium-sized bowl, combine 1 ½ cups all-purpose flour, 1 teaspoon baking powder, ½ teaspoon baking soda, and ¼ teaspoon salt. Mix it together gently with a whisk.
In a large bowl, use your KitchenAid Hand Mixer to cream together 4 tablespoons softened butter and ¾ cup granulated sugar until it becomes light and fluffy. This should take about 2 to 3 minutes.
Add 1 large egg, 1 teaspoon vanilla extract, ¼ cup sour cream, and ¼ cup reserved pineapple juice to the creamed mixture. Beat until everything is well incorporated.
Gradually add the flour mixture to the wet ingredients. Mix until just combined—do not overmix to keep it light and fluffy.
Spoon the batter over the pineapple rings, ensuring it covers them evenly. Gently spread to create a smooth layer.
Transfer the cake pan to the preheated oven and bake for 35 to 45 minutes. You’ll know it’s done when a toothpick inserted in the center comes out mostly clean. It should be golden brown.
Remove the cake pan from the oven and let it cool for 5 minutes. This allows it to set slightly before flipping.
To flip, place a cake platter over the cake pan. Carefully turn it upside down and wait about 30 seconds. Then lift the cake pan away to reveal your beautiful creation.
Let the cake cool completely before slicing and serving. The wait will be worth it!