Preheat the oven to 180 deg C. Grease a 23cm round cake tin and line the bottom with baking paper (so that it slightly goes up the sides a centimeter or so).
In a saucepan, combine the sugar and the salt, plus just enough water to wet the sugar. Cook over a medium heat until you have a light caramel, then remove immediately and pour into a cake tin.
Cut the pineapple into pieces (or rings) using a pastry cutter and place as a single layer in the caramel. Ensure that the caramel is cool before doing this.
To make the cake, combine the butter and sugar in a bowl. Using an electric mixer, cream until light and fluffy. Add the eggs and egg yolks, one at a time, scraping down the sides of the bowl and beating well between each egg.
Mix all of the dry ingredients together and add to your mix, combining well. Pour the cake batter over your pineapple and cook in the oven for 30-35 minutes, or until cooked through. Turn the cake out onto a cooling rack.
To prepare the cherries, place the dessert wine, sugar and spices in a saucepan and bring to the boil. Add the cherries and turn down the heat, then poach for about 25 minutes. Remove from the heat and refrigerate until ready to serve.
Mix the mascarpone, cream and vanilla together and whisk until thick, then refrigerate until ready to serve.