• Preheat the oven to 325°F.
• Grease a Bundt pan generously with butter, oil or shortening and sift in enough flour to coat. Dump out any excess flour and set the pan aside.
• In a mixing bowl, combine the flour, baking powder, baking soda, and salt, then set aside.

Prepare the Cake Batter:

• In the mixing bowl of a stand mixer, add the butter and granulated sugar.
• Mix with the paddle attachment at high speed until pale in color with a sandy texture.
• Add the eggs one at a time, mixing to combine.
• Add the egg yolks and continue mixing at low speed.
• Add the vanilla and pineapple juice and mix until combined.
• Add the sour cream and continue mixing.
• Add half the flour mixture to the batter, then add the milk and mix in the remaining flour mixture.
• Increase to medium speed (around speed 4 or 5) and beat for a minute, then set aside. *Note: The batter will come together and resemble soft serve ice cream once completely incorporated.
• In a small bowl, combine the brown sugar and cinnamon.

Assemble the Bundt Cake in the Pan:

• Pour the melted butter into the bottom of the greased Bundt pan, then sprinkle it in the brown sugar cinnamon mixture.
• Arrange the pineapple halves cut side up into the grooves of the Bundt pan, gently pressing into the butter/brown sugar mix and alternating with cherries in between each pineapple slice.
• Pour the batter over the pineapple/cherries and spread evenly using a spatula.

Bake the Bundt Cake:

• Bake on the center rack for 70 to 90 minutes, covering with a piece of foil after 35 minutes of baking to avoid burning the 'bottom.'
• Once a toothpick inserted into the center comes clean, remove it from the oven.

Cool and Slice:

• Allow to sit for 10 minutes, then carefully invert the pound cake onto a serving plate.
• Don’t eat it yet – it’s very hot! The cake must cool for at least an hour at room temperature before serving.
• Once the cake is cool, slice and serve.