Preheat oven to 350 degrees F.

To make the cake, in a large bowl whisk or sift together the flour, baking powder, and salt. Set aside.

In the bowl of a stand mixer, beat 3/4 cup butter until light, about 3 minutes. While the mixer is running, slowly stream in the sugar and beat on high until light and fluffy, about 5 to 8 minutes. Stir in the vinegar and 2 teaspoons vanilla extract. Add the eggs, one at a time, mixing well after each addition. Make sure to scrape the sides and bottom of the bowl with a rubber spatula as needed. Stir in the pineapple juice and mix until evenly incorporated. The mixture might look curdled after you've added the pineapple juice, but that's okay. Add the dry ingredients alternately with the buttermilk, starting and ending with the dry ingredients until well combined. The batter will by slightly thinner than you're used to. Set aside.

To make the topping, set a 10-inch cast iron skillet over medium-high heat along with the remaining butter. Once melted, whisk in the remaining vanilla, brown sugar, and brandy and cook until dissolved, about 1 minute. Remove from the heat and arrange the pineapple slices into the caramel in an even layer. Arrange the cherries among the pineapple slices, placing some in the middle of the rings and around the outside. Pour the cake batter evenly over the fruit and caramel. Place the skillet over a baking sheet, to catch any drips. Bake until cake is golden brown and set, and a toothpick inserted in the middle comes out clean, about 30 to 35 minutes. Let cook for 10 minutes and then place a large plate or platter over the skillet. Carefully flip it over and let the cake sit upside down for 15 minutes and then lift up the skillet. The cake should invert perfectly. Serve warm or at room temperature. Any leftovers can be wrapped well and stored in the fridge for up to 3 days. Enjoy!