Preheat your oven to 350°F (175°C). Grease a 9-inch round cake pan with butter.

Melt 4 tablespoons of unsalted butter with ¾ cup of brown sugar until bubbly in a saucepan. Pour into the greased pan and layer with pineapple rings and cranberries.

Whisk together 1 ½ cups of flour, 2 teaspoons of baking powder, and ½ teaspoon of salt in a bowl.

Beat 6 tablespoons of butter with 1 cup of sugar until fluffy. Add 2 eggs and 1 teaspoon of vanilla extract, one egg at a time.

Gradually combine dry ingredients and ½ cup pineapple juice, starting and ending with flour. Fold in ½ cup sour cream.

Pour the batter over the topping in the pan. Bake for 40-45 minutes until a toothpick comes out clean.

Cool in the pan for 10 minutes, then invert onto a serving plate.