Preheat the oven to 350 degrees.

Arrange paper towels on a flat surface or large baking sheet. Place the pineapple slices and cherries on the paper towels and pat dry. Set aside.

Pour the melted butter into the bottom of 9-inch round cake pan. Brush the butter up the sides of the pan.

Sprinkle the brown sugar over the butter and spread out in an even layer. Arrange the pineapple slices over the brown sugar – one full round in the middle and half circles around the center piece. I used 11 half slices around the center round piece.

Arrange the cherries in the pineapple slices. Press the pineapple and cherries down with a spatula to ensure they press into the sugar (this ensures you get vibrant red and yellow color on top).

To make the batter, in a medium bowl, whisk together the flour, baking powder, baking soda, and salt.

In a separate bowl, whisk together the milk, sour cream, reserved pineapple juice, and vanilla.

In a mixing bowl fitted with the paddle attachment, beat the butter and granulated sugar together until light and fluffy.

Beat in the eggs, one at a time. Beat in 1/3 of the milk mixture and then 1/3 of the flour mixture. Repeat 2 more times until everything is blended. Finely chop the leftover pineapple pieces and fold them into the batter.

Pour the batter over the pineapple slices and cherries and smooth the surface.

Bake for 30 minutes. Loosely cover with foil and bake for 12 to 15 more minutes, until a wooden pick comes out clean, or with little moist bits clinging to it.

Cool the cake in the pan, on a wire rack, for 20 minutes.

Run a butter knife or offset spatula around the edges of the pan. Place a plate over the cake pan and flip. If the cake doesn’t release freely, gently tap the bottom of the pan.

Cool completely before serving.

Refrigerate leftovers in an airtight container for up to 4 days, or freeze for up to 1 month.