Drain the can of pineapple slices over a 4-cup liquid measuring cup and reserve the juice. You need 1 full cup of juice for the cake batter; if you get less, add water to make up the difference. Remove the stems from 10 maraschino cherries and set aside. Have 1 or 2 extra cherries ready in case one falls in the wrong spot.

In a small mixing bowl, combine 2 cups of all-purpose flour, 1 tablespoon baking powder, ½ teaspoon fine grain sea salt, and ¾ cup granulated sugar. Stir with a spatula to disperse the baking powder and salt evenly through the flour.

In a medium mixing bowl, combine ½ cup of neutral oil, 3 large eggs, and 1 teaspoon vanilla extract. Use a fork to break up the egg yolks and lightly combine with the oil. Do not whisk or over-beat.

Add about half of the egg and oil mixture to the dry ingredients and fold with a spatula. The fat will coat the flour, which helps prevent lumps. Next, add about ⅓ of the pineapple juice and fold to combine. Continue alternating the remaining egg/oil mixture and pineapple juice in small additions, folding gently between each. Stop folding as soon as the flour is incorporated. A few small lumps are fine. Do not overmix. Set the batter aside to rest while you make the caramel base.

Set the Possible Cooker Pro to Sear/Sauté on High and press Start. If you have the Pro Plus model, set the temperature to 400℉/200℃ on the Sear/Sauté function. Add ½ cup of salted butter to the pot and let it begin melting.

Once the butter is mostly melted, add 1¼ cups of packed light brown sugar and ¼ cup of water. Stir gently with a spatula to combine the butter, sugar, and water. Let the mixture come to a boil on its own while you prepare the pineapple.

Have a cake tester, thin skewer, or similar heat-safe tool ready. Once the brown sugar mixture is boiling, carefully drop a pineapple slice into the center of the pot. Immediately drop a maraschino cherry into the center hole of the pineapple slice. Use the tool to nudge the cherry into the center if needed. Continue with the remaining pineapple slices and cherries, arranging them in the pot in a pattern that will look good when flipped.

Press each pineapple slice down so it's submerged in the boiling brown sugar syrup. Let the syrup bubble up over the top of the pineapple for a few seconds to help lock everything in place.

Starting in the center, slowly pour the prepared cake batter over the pineapple slices, working your way out to cover everything in an even layer. If any pineapple slices float up, gently press them back down into the batter so they stay near the bottom of the pan.

Place the lid on the pot and seal it. Turn the Possible Cooker Pro off, then turn it back on and switch to the Bake function. Set the temperature to 250℉/120℃ and the time to 30 minutes. Press Start. Do not remove the lid during baking as the steam is needed for a tender cake.

When the 30 minutes is up, remove the pot from the base and place it on a heat-resistant surface or cooling rack. Take the lid off and let the cake rest for 5 minutes. The top may look slightly uneven but will settle as it cools.

After the 5-minute rest, run a silicone or heat-safe tool around the edge of the pot to release the cake from the sides. Let the cake cool at room temperature for 20 to 30 minutes. Do not let it cool much longer than 30 minutes or the brown sugar mixture can begin to stick to the bottom of the pot.

Place a sheet of parchment paper over the top of the pot, followed by a sheet of aluminum foil for extra support. Gently shake the pot back and forth to make sure the cake has released. Place your hand flat on top of the parchment and foil, carefully invert the pot, and let the cake drop onto a serving platter or large plate. Remove the foil and parchment. Slice and serve warm or at room temperature.