Preheat oven to 350ºF. Pour the rum over raisins and set aside.
Melt 5 Tbsp butter and add to 9-inch spring-form pan (you can also use a square or rectangle - be creative!). Tilt to coat bottom and sides. Sprinkle with 1/ cup sugar and arrange pineapple slices - you can overlap if you like. Arrange spiked raisins over top in open nooks.
In a large microwaveable bowl, microwave coconut milk and 4 Tbsp butter in 20-second intervals just until melted, but not hot. Whisk in remaining sugar. Whisk in eggs, lime zest and juice, and vanilla.
Whisk together flour, baking powder, and spices. Add flour mixture in 3 additions to milk mixture, whisking until smooth.
Pour batter over pineapple and spread to flatten top. Tap pan on the counter to remove any bubbles.
Bake until cake is golden and set in middle, about 1 hour. Let cool then invert on to platter and remove form. Serve warm with whipped cream or ice cream.