The Electric Maze Task (EMT) is a novel planning task designed to allow flexible testing of planning abilities across a broad age range and to incorporate manipulations to test underlying planning abilities, such as working-memory and inhibitory control skills. The EMT was tested in a group of 63 typically developing 7- to 12-year-olds. Participants completed 4 mazes designed to alter working-memory demands (by increasing the number of steps required from 6 to 8) and inhibitory control demands (by using a modified Dimensional Change Card Sort task) and 3 standardized measures using the Cambridge Neuropsychological Test Automated Battery. The EMT was found to correlate with measures of visual memory, working memory, and planning. The 6-step mazes were simpler for participants to solve and mapped on to performance on the visual memory task. The 8-step mazes were more difficult and mapped on to performance on the spatial working-memory and planning tasks. Children who were 10 to 12 years old were also better than 7- to 9-year-olds at solving all mazes, as evidenced by fewer errors and fewer errors later in solving the mazes. Younger children also struggled more than older children after a rule switch. Performance on the maze task differentiated 7- to 12-year-old children with better planning skills, and manipulations of the maze task were successful in altering the working-memory and inhibitory control demands.