Jody Morris' side came into Saturday's semi-final second leg - which was played at Stamford Bridge due to the senior side facing Stoke City away earlier in the afternoon - with a 2-1 lead from the first leg.
In that game, Reece James and Ike Ugbo had given the Blues a comfortable 2-0 lead at White Hart Lane, but a late goal from Kazaiah Sterling and a penalty save from Spurs' in-form goalkeeper Brandon Austin ensured the north Londoners went to west London with hope in their heart.
But any optimism the visitors had were quickly crushed by Chelsea when Ugbo converted a cross from the right to hand the Blues an early lead.
Tottenham continued to probe forward, though, and were handed the perfect opportunity to restore parity and haul themselves back into the contest when Sterling won a penalty.
But the Spurs forward couldn't convert his spot-kick as goalkeeper Jared Thompson dived correctly to his right and saved with his outstretched hand.
Perhaps buoyed by their domination of the first leg and, indeed, the senior side's late victory over Stoke at the bet365 Stadium just hours before, Chelsea reacted by hitting the woodwork through George McEachran before they were handed a penalty of their own for a foul on Dujon Sterling by Nick Tsaroulla.
Ugbo calmly dispatched the spot-kick to hand Chelsea a 5-1 aggregate lead and net his seventh Youth Cup goal of the campaign ahead of the break.
The interval appeared to spur the hosts on further, and Chelsea re-emerged fully focused as they ran riot in the second half - scoring a further four times.
Dujon Sterling and substitute Callum Hudson-Odoi got on the scoresheet before Ugbo completed a hat-trick in fine fashion soon afterward.
Tottenham got one back through Jack Roles, but Juan Castillo's late strike ensured Chelsea booked their place in the FA Youth Cup final in superb fashion.