Attack the instant you win it. Get the head up on the turnover, go forward while the other team is still facing the wrong way, and get somebody ahead of the ball. The reward is for going early, not for keeping the ball tidy.
Play 4v4 on a 40x28m pitch with a goal at each end and no keepers. Normal football, with one condition: a goal scored within about eight seconds of winning the ball counts double. Count out loud so the players can hear the clock. Do not assign positions and do not tell anyone to stay back, since the whole point is that they learn what the moment demands rather than being placed where an adult thinks it is safe. If a team cannot get to the goal in time, play simply carries on. Short games of five or six minutes, rotate the teams, and never eliminate anybody.
Transition is the fashionable word in football and it travels down the age groups faster than it should. Coaches watch a senior side counter-press and win the ball back in five seconds, then try to install the same idea in a group of nine-year-olds who are still learning to control a bouncing ball.
The governing-body guidance for this age is refreshingly direct about it. Young players change possession constantly, precisely because their technique and decisions are still forming, but they do not yet have the game understanding to execute a coordinated counter-attack. Teaching them the adult version does not accelerate anything.
Worse, the usual fix makes it actively harmful. To keep the counter under control the coach starts organising: you stay there, you hold that position, nobody go past that line. The game gets tidier and the players get less of the practice they came for.
What is recommended instead is deliberately small: a game with one specific objective attached to the instant possession is won. Run to that line. Score in that goal. The child does not need a model of transition, only a reason to go, and a reason produces the behaviour that the model was trying to describe.
The double-goal window is that reason made concrete. Nobody has to be told to look up quickly, because looking up quickly is now worth something on the scoreboard, and at this age the scoreboard is a more reliable teacher than any instruction.
One detail is worth coaching directly, because it rarely appears on its own: somebody has to run past the ball. Young teams transition by all moving forward together and supporting from behind, which advances the ball without ever threatening the goal.
And the honest limit: if the quick attack is not there, it is not there. A team that learns to look, go when it is on and settle when it is not has learned the actual skill. Forcing it every time is just a different kind of giving the ball away.
Save it to your private drills, then change the animation, adjust positions, swap equipment, or drop it into a session block. Or start from a blank pitch and build your own.