Preheat your oven to 350°F (175°C). Grease the 9-inch round cake pan with butter and sprinkle the bottom evenly with brown sugar.
Arrange the pineapple slices on top of the brown sugar, placing cherries in the center of each slice.
In a mixing bowl, cream together the softened butter and granulated sugar until light and fluffy using an electric mixer or whisk.
Add the eggs one at a time, mixing well after each addition, then stir in the pineapple juice and vanilla extract.
In a separate bowl, combine the flour, baking powder, and salt. Gradually add this dry mixture to the wet ingredients, mixing until just combined.
Pour the cake batter over the pineapple and cherries in the pan, spreading it evenly.
Bake in the preheated oven for 40-45 minutes, or until a toothpick inserted into the center comes out clean.
Remove the cake from the oven and let it cool in the pan for about 10 minutes. Then, carefully invert the cake onto a serving platter while it's still warm.