Invented in Oakland - Oakland

A number of interesting things have been invented in Oakland over the years, and Oakland has been home to various inventors.

Rocky Road ice cream - invented during the depression by William Dreyer (possibly borrowing the idea from partner Joseph Edy or Fentons) (Wikipedia)
Popsicles - invented by 11 year-old Frank Epperson in 1905 (patented 1923) (Wikipedia)
fortune cookie folding machine - invented in 1973 by Cal grad Shuck Yee (Wikipeda). [ More correct to say he invented a fortune cookie folding machine. There's a 1974 patent by Edward Louie improving on earlier machines dating back as far as 1963/1966. According to this PRI podcast, the fully automatic machine wasn't invented until 1981. ]
Mai Tai - invented in 1944 by "Trader Vic" Bergeron (Wikipedia)
Corn Nuts - invented in 1936 by Albert Holloway
Jelly Belly - predecessor of the popular jelly beans created by Herman Goelitz Candy Company

Mai Tai photo CC-A by duluoz catspopsicle patent #1,505,592 USPTODreyer's Rocky Road photo CC SA-BY from Our Oakland

fantasy football - invented by Raiders' partner Wilfred "Bill" Winkenbach, Bill Tunnell, Raiders PR manager, and Scotty Stirling, reporter. The initial league was called GOPPPL (Greater Oakland Professional Pigskin Prognosticators League). Later leagues met at King's X Bar (now Kona Club) on Piedmont Avenue. (Wikipedia)
"the wave" - might have been invented by "Crazy George" Henderson. First televised, October 15, 1981 at an A's game (Wikipedia)

CC BY-SA 4.0 Alan Josephs

scraper bikes - invented by Tyrone Stevenson, Jr. (Wikipedia)
electric crematorium - at Chapel of the Chimes
the squeegee - Ettore Products, Co. headquarters is in Alameda, but Ettore Steccone lived in Oakland when he developed the squeegee in 1936
electric alarm clock for schoolhouses - invented by educator Simeon P. Meads
covered dustpan with raised lip - patented by Emma L. Dietz and Mary A. Dietz in 1881

Some things that weren't necessarily invented in Oakland, but have Oakland connections:

Pelton waterwheel - invented by Lester A. Pelton, "the father of hydroelectric power", who retired to Oakland
the "high five" - invented by then L.A. Dodger Glenn Burke and teammate Dusty Baker
brick making - the Remillard Brick Company patented various improvements for brick-making