Pineapple Upside Down Cake

Topping

• 140 g brown sugar
• 115 g unsalted butter, diced, room temperature
• 6 - 7 slices canned pineapple, in juice, plus 140 g juice

Batter

• 170 g icing sugar
• 170 g unsalted butter, diced, room temperature
• 2 large eggs
• 3 tbsp dark rum, divided
• 1 tsp natural vanilla extract
• 240 g all-purpose flour
• 2 tsp baking powder
• ⅛ tsp salt