Cuba, who have failed to progress into the next round, had an injury scare after just seven minutes when goalkeeper Sandy Sanchez dropped to the floor clutching his knee despite not being involved in a challenge.
Minutes later Ricardo Pereira received a short pass from Bruma in the box and launched the ball into the back of the net and gave Portugal the lead.
Soon after Aladje found the back of the net from a Bruma shot, but he was wrongly ruled offside.
However, Portugal managed to double their lead before long when Bruma laid on a square ball for Aladje in the box to stroll into the net.
Cuba tried to pull themselves into the game five minutes before the end of the first half through Daniel Saez, but his long-range effort curled just wide.
Just before the break, Portugal added to their scoreline from a play starting with Toze, who fizzed the ball into the box from the right-hand side to find Bruma, who then strode through the Cuba defence to tap home.
Tiago Silva almost opened the second-half scoring with a swivel in the box to line up a shot on goal, but his effort hit the post.
At the other end, Osmany Capote threaded a ball onto the feet of Jordan Santa Cruz, but the goalkeeper was able to spread out and block the shot, leaving Cuba with no hope of getting on the scoresheet.
Portugal made it 4-0 when Silva charged down the right to whip the ball into the box to find Bruma, who curled home to take his personal tally to five goals so far in the competition.
Toze made it five minutes later by hitting the ball into the left-hand corner of the net.