Step 1

Place a rack in middle of oven and preheat to 350°. Place a 13x9" metal baking pan by the stove. Cook brown sugar, butter, vanilla extract, and salt in a small saucepan over medium heat, stirring occasionally, until butter is melted and mixture is bubbling, about 5 minutes. Pour caramel into baking pan and spread to evenly coat bottom with a heatproof rubber spatula, nudging into corners.

Step 2

Arrange pineapple slices on top of caramel without overlapping. Place a cherry in the center of each pineapple ring. Set aside.

Step 3

Whisk flour, baking powder, salt, and mace in a medium bowl. Whisk eggs and vanilla extract in a small bowl.

Step 4

Beat butter and granulated sugar in the bowl of a stand mixer fitted with paddle attachment on medium-high speed until light and fluffy, about 4 minutes. Add egg mixture in 4 batches, beating on medium speed 30 seconds after each addition and scraping down bowl as needed. Reduce mixer speed to low and beat in dry ingredients in 3 additions, alternating with sour cream in 2 additions, mixing 30 seconds after each addition. Fold batter a few times with a clean spatula, scraping down sides to make sure everything is well mixed. Scrape batter into reserved baking pan; smooth surface.

Step 5

Bake cake until golden and a tester inserted into the center comes out clean, 40–50 minutes. Transfer pan to a wire rack; let cake cool in pan 15 minutes. Run an offset spatula along edges of cake to loosen. Set a large platter over pan and flip over to release cake; carefully remove pan. If any fruit or cake sticks to pan, scrape it off and press back onto top of cake. Serve warm or room temperature.Do ahead: Cake can be baked 3 days ahead. Store airtight at room temperature.