A quick sketch: cake pan
It is an eight inch circle with inch and a half walls and rolled edges. The dull thunderhead-grey aluminum is coated in a nonstick film and signs of regular use. A flat half-inch wide strip of metal runs along the bottom and up the walls, starting at a rivet in the middle of the pan to end in an overhang slightly beyond the edge. Only attached by one point, the strip rotates freely, sweeping the bottom of the pan like an old radar display. This arm allows for two major boons: the ability to quickly and evenly spread grease around the pan, and (both similar to and because of the previous point) perfect cake extraction every time. Spill a line of oil along the edge of the arm, and give it a few rotations at the beginning to grease it up, then one more spin at the end of baking to release the cake. It is an intuitive mechanism whose dependability lies in the extremely basic design. Though the adition of a bottom-sweeping arm to circular cake pans may seem frivolous or merely neat, it is without a doubt a brilliant piece of mechanical ingenuity that makes the process of baking more accessible, reliable, and ultimately simpler.