pineapple upside-down cake

INGREDIENTS

• 1 tablespoon dark rum
• 1/2 medium pineapple, peeled, quartered lengthwise, and cored
• 3/4 stick unsalted butter
• 3/4 cup packed light brown sugar
• 1 1/2 cups all-purpose flour
• 2 teaspoons baking powder
• 1/4 teaspoon salt
• 3/4 stick unsalted butter, softened
• 1 cup granulated sugar
• 2 large eggs
• 1 teaspoon vanilla
• 1/2 cup unsweetened pineapple juice
• 2 tablespoons dark rum for sprinkling over cake