Coat the cooking cake pan with a regular amount of cooking spray and leave aside until needed. In a saucepan with the stove on medium heat, heat the brown sugar and add one stick of butter. Whisk every so often till the sugar has dissolved completely. Bring to a boiling point and cook till the caramel starts to thicken and turns to a dark brown colour. Cook this for about 3 minutes. Remove the saucepan from the heat and whisk in some rum and 1 teaspoon of salt. Pour the caramel into the cake pan and use swirling motions until the pan is coated. Set the cake pan aside and let it cool.
Preheat the oven at 175 C (350 F). In a medium sized bowl, mix together with a whisk baking powder, the remaining salt, flour and cinnamon. In a larger bowl, mix together the granulated sugar, and the remaining butter with an electric mixer on medium until it is looking fluffy and light.
Arrange the pineapple rings on top of the caramel in the prepared cake pan. Fill the spaces inbetween the rings with what pineapple chunks are leftover. Carefully pour the batter over the pineapple and smooth over the top using the rubber spatula.
Bake your cake until you can use a toothpick and it comes out with no batter on it. Cook this for 50 minutes. Move pan to a rack and let cool for 30 minutes. Run a knife around the sides so the cake can loosen from the pan and put on a large sized serving plate.