Originally the trademark name of a tube pan with fluted sides, "bundt" is now the general name of that style of cake pan. Classic bundt pans hold 12 cups of batter and are 10 inches in diameter by 3.5 inches tall. Created in 1950 by H. David Dalquist at the request of a women's group that wanted to bake kugelhopf, a ring-shaped German bread, the bundt pan became a sensation when used in the 1966 Pillsbury Bake-Off contest by Ella Helfrich for her Tunnel of Fudge recipe. Dalquist's other notable invention: the rotating microwave oven carousel.
To prevent a cake from sticking to this pan, it's extremely important that all the creases of the fluted sides are well greased before pouring in a batter.