A fluidized catalytic cracking process includes fluidizing hydrocarbon and catalyst in a riser having an extension mounted to and surrounding at least a portion of or extending adjacently to the riser, cracking the hydrocarbon with the catalyst in the riser to form a substantially cracked stream, further cracking the hydrocarbon with the catalyst in the extension, wherein the hydrocarbon and the catalyst reverse direction in said extension, and separating the cracked stream from the catalyst.