Posh Warm Spiced Pineapple Upside Down Cake

This is one of those puddings I remember from my childhood, Probably one of the British classics that we all seem to have fond memories of. When I was very young, a pineapple always reminded me of distant exotic lands.
I've called this recipe POSH, It isn't really, I've added some Rum to the sauce, and made a granita with the pineapple trimmings, But, In truth, this is just a blooming good pudding.
This recipe will serve 8-10 people ( you can halve these quantities to make 4-5 pudding if desired )
Shopping List
2 medium sized pineapples
A small amount of rapeseed oil
A sprinkling of caster sugar for caramelizing the pineapple
Ingredients for the Sponge
125g crushed brazil nuts ( you can do this in a food processor )
250g of Butter
1 Tablespoon of clear honey
150g of plain flour
1/2 teaspoon of salt
1/2 teaspoon of baking powder
1/2 teaspoon of ground allspice
1/2 teaspoon of ground ginger
1/2 teaspoon of nutmeg
1/2 teaspoon of ground cinnamon
200g of caster sugar
6 egg whites