Upside-down pineapple and banana cake

Ingredients

• Topping
• 1 cup brown sugar
• 90 grams butter, chopped
• 440 grams can thin pineapple slices, drained
• 1 firm ripe banana, thickly sliced
• Upside down pineapple and banana cake
• 100 grams butter, chopped, at room temperature
• 1/2 cup brown sugar
• 2 eggs
• 1 1/2 cup self-raising flour
• 1 teaspoon ground cinnamon
• 225 grams can crushed pineapple
• 1/4 cup sour cream
• cream, to serve (optional)