This was great fun to make but it was quite tricky so I've included my tips in italics, Anne
(I used a shallow 20cm round tin, I recommend either making a couple of small ones, to ensure the final jelly doesn't fall apart on turning out, or if only making one using the left over jelly for a trifle)
Add cream to pineapple mixture a little at a time, whisking to combine. Spread cream mixture on top of jelly cubes to fill any gaps. (The dessert would be stronger if the "stained glass" jelly shapes were covered in the pineapple mix but I wanted to see if the colour would be more vibrant if it just filled the spaces, luckily everything held together on upturning!)
Maybe decorate with hundreds and thousands.
Tip: To remove the coloured jellies from their bar tins, and the final dessert from the dish/tin I briefly sat the tins in a shallow dish of hot water to loosen the jelly, Anne.
Have fun making different coloured mosaics with the jelly pieces!! Anne