Drain the pineapple rings, reserving the syrup. I used about 8 rings for the stew. Reserve three rings of pineapple for decoration and chop the rest.
Cook together with sugar for about 5 minutes until pineapples are translucent. Let cool.
Beat cold heavy whipping cream at high speed with sugar until soft peaks form. Put the whipped cream in a piping bag.
You can use a homemade or store-bought sponge cake. (I used homemade 4-ingredient sponge cake)
Slice the sponge cake into two or three layers. I used only two slices. You can also make a 3-layer cake if you want.
Sprinkle some pineapple syrup over each of them, especially around the edges. You can also use sugar syrup or pineapple juice.
Place the first layer on a plate (topside down).
Spread a layer of whipped cream and arrange pineapple stew on top and add more whipped cream to fill the gaps.
Cover with the second layer. Sprinkle the pineapple syrup, as needed.
Now cover the whole cake with the remaining whipped cream smoothly with a palette knife.
Decorate as you like with whipped cream, pineapple, and cherries or as desired.
Cover and refrigerate for 3-4 hours and serve chilled.