Bracknell's young stars edged hosts Reading to the silverware on tries scored in the group stage after the final ended 0-0.
The tournament win backs up success at the Maidenhead festival the previous week, highlighting future stars to progress through the ranks at Lily Hill Park.
Bracknell topped the standings after the group stages following wins against Maidenhead (5-0), Redingensians (5-0) and Newbury (15-5).
They also drew 0-0 with Wallingford.
Alex Macdonald helped himself to a brace of tries while Sam Clough, Matt Dalrymple, Alexander Robinson and Harry Grange all also touched down in the group stages.
The first semi-final saw Reading beat Maidenhead before Bracknell took the field against Reading Abbey for their chance to join the hosts in the final.
And the U12s secured their spot in the trophy decider when a Grange try secured a 5-0 win.
Roll of Honour
Mini festival of rugby award winners:
Under-seven (U7) A: Newbury
Under-eight (U8) A: Maidenhead
U8-B: Tadley and Maidenhead
Under-nine (U9) A: Beaconsfield
Under-10 (U10) A: Redingensians
Under-11 (U11) A: Beaconsfield
Under-12 (U12) A: Bracknell