Heat oven to 350 degrees F.
In large mixing bowl sift, then whisk together dry ingredients, until combined. Set to side.
In medium mixing bowl, whisk together egg yolks, rum, vanilla and ¼ cup of the sour cream. Set aside.
Add butter and remaining sour cream just until dry ingredients are moistened.
Increase speed and add yolk mixture in 3 batches, mixing well after each addition. Set batter to side.
In 10” cast iron skillet, melt butter for topping over low heat. Sprinkle brown sugar evenly over butter and allow to sugar to dissolve. Don’t stir. When sugar has dissolved, remove skillet from heat and place one pineapple ring in center of pan.
Place remaining pineapple rings around edges of pan. Set one cherry in center of each pineapple ring.
Gently pour batter over pineapples, spreading evenly.
Bake 35 minutes or until inserted pick come out clean.
Allow cake to cool in skillet for 10 – 15 minutes then gently run metal spatula around sides of skillet and carefully invert skillet onto cake plate and allow to cool completely before serving. Although, I like mine warm.