This is easy but time consuming, so good if you've got the evening at home or all day.
I think I originally found a photo of these on Pinterest or Twitter, then I experimented 2 or 3 times to work out how to do it.
Pre-heat the oven to Gas Mark 1
Get a ripe pineapple
Get a decent large serrated bread knife
Slice the ends off
Slice the skin off
Then slice really thin slices, as thin as you can. I wanted to use a mandolin but it's not wide enough for a pineapple, maybe other brands are wider so give it a go.
When you have sliced up as many "flowers" as you want, or the whole pineapple, grab the baking tray.
If you have a non-stick muffin tin, then you won't need to oil it, otherwise spray it with oil or very lightly oil with olive oil.
Lay the pineapple slices in the holes
If you need to, you can use 2 or 3 muffin tins on different shelves in the oven.
Leave them in the oven for 30 minutes, then check, rotate the pan, set the timer got 30 minutes again. Repeat.
Should take 2 hours, or about that, after 2 hours turn the oven off and leave them in there to cool down and dry out more.