While the water falls v increases and h decreases, so the kinetic energy increases and the gravitational potential energy decreases, and this happens in a way that the total energy is always the same. (If there is no friction)
Baking a cake creates a endothermic reaction. When heated, the baking soda/powder reacts, the eggs change form, and everything else follows suit. The baking soda/powder creates the rising of the cake.