Pre-heat oven to 350F (180C). To help keep the caramel and fruit bottom from sticking it is a good idea to line the pan with parchment paper. A good tip is to first wet the paper then scrunch it up and shake out any excess moisture before lining the cake pan.
PINEAPPLE BASE
Pour the melted butter into the bottom of a 8 or 9 inch (20-23 cm) cake pan, brush the sides with a little of the butter, the rest will remain on the bottom of the pan, sprinkle the brown sugar on top of the melted butter, then place the sliced pineapple on top and in the middle of every slice place a maraschino cherry, if desired. Set aside.
FOR THE CAKE
In a medium bowl whisk together the flour, baking powder, baking soda and salt. Set aside.
In a large bowl beat together the eggs, egg yolk and sugar until light and fluffy about 3-4 minutes, then add the vanilla, yogurt and milk beat until smooth. Add the whisked flour mixture and beat until smooth about 1 minute. Pour the batter evenly over the pineapple and bake for approximately 30-45 minutes, test for doneness with a toothpick. Let cool or serve warm. Let the cake cool before turning upside down on a large plate, then cut and serve. Enjoy!
Notes
I like to use a springform cake pan it makes it easier to remove the cake.
How to store it
The cake should be stored in the fridge, in an airtight container or wrapped well in plastic wrap or foil, bring it to room temperature before serving. Remove from the fridge about an hour or so before serving. It will last up to 3-4 days in the fridge.It can also be frozen. Wrap the completely cooled cake with plastic wrap and place in a freezer safe bag or container. It will keep for 2-3 months in the freezer. Thaw the wrapped cake at room temperature, it should take about an hour to thaw.