FOR THE BUTTERSCOTCH-PINEAPPLE LAYER
3 oz (6 Tablespoons or 3/4 stick) butter (salted is fine here)
3/4 cup packed dark brown sugar
heavy pinch of salt if using unsalted butter; wee pinch if using salted butter
about 6-8 oz chopped pineapple, (fresh or canned in juice)
FOR THE CAKE
12 oz unsalted butter
18 oz granulated sugar
2 1/2 teaspoons best quality vanilla
1 gently rounded teaspoon sea salt
5 eggs, , beaten
13 oz cake flour
1 teaspoon baking powder
8 oz chopped pineapple, (fresh or canned in juice)
2 oz sour cream
Make sure all your refrigerated ingredients are at cool room temperature.
Spray a 12-cup Bundt-type pan with pan spray. Flour it well, and tap out all the excess flour.
Make sure your oven rack is positioned one notch below the middle of the oven. Preheat the oven to 350F.
FOR THE CARAMEL PINEAPPLE LAYER
Melt the butter in a small sauce pan.
Add the sugar and salt, and stir until dissolved.
Let the mixture come to a boil. When nice and bubbly without any butter sloshing around the edges of the sugar, pour evenly into the prepared pan.
Arrange the cut pineapple on top however you want. I just used chopped, but half-rounds alternating in direction would look lovely.
Set pan aside.
FOR THE CAKE
Whisk together the cake flour and baking powder until well combined. Set aside.
Puree pineapple and sour cream together in a blender. Set aside.
Cream the butter, sugar, salt and vanilla until light and fluffy, scraping the bowl as often as necessary.
With the mixer on medium speed, add the beaten eggs a little at a time, beating well after each addition, until completely incorported. Stop to scrape down the sides of the bowl as necessary.