Preheat the oven to 180°C.
Line an 18cm square baking tin with parchment paper and arrange pineapple rings on the base.
Process butter and sugar in a food processor until pale and fluffy.
Add eggs one at a time, beating well after each addition.
Beat the flour into the mixture.
Spoon the batter over the pineapple and smooth the surface.
Bake for 10-15 minutes until golden-brown.
Cool slightly before removing parchment and slicing.
Simmer chilli flakes, pineapple juice, honey, and lime juice in a pan for 6 minutes until syrupy.
Place cake slices on a plate and pour the syrup over them.