Preheat the oven to 350°F (180°C).
Blend pineapple with water until nearly smooth.
Mix blended pineapple with cake mix; beat 1 minute.
Pour into ungreased bundt or loaf pans.
Bake 40–45 minutes until golden.
Cool upside down for 1½ hours.
Run knife around edge, release cake.
Slice with serrated knife and serve.
