The Indomitable Lions showed remarkable character to come from behind and beat Egypt 2-1 in a brilliant game at the Stade de l'Amitie in Libreville with Nicolas Nkoulou and Vincent Aboubakar scoring to spark wild celebrations.
It was the first time a team had come from behind to win the final since 1994 and it was a first continental title for Cameroon since 2002, their fifth in total.
The triumph, witnessed by a crowd in the Gabonese capital made up of a majority of Cameroonians, completed a remarkable journey for a side who had been written off prior to the tournament.
Eight players, notably the Liverpool defender Joel Matip and the Schalke striker Eric Choupo-Moting, had refused call-ups to the squad, leaving Broos to work with a young and inexperienced side.
That team had already eliminated the hosts Gabon, much-fancied Senegal and Ghana en route to the tournament finale, where they claimed Cameroon's first win against Egypt in a Cup of Nations final at the third attempt.
"I brought in some new young players and we started working. We did a good job and now today we have a team," said Broos after Sunday's match.
His man management has been remarkable and on Sunday it was notable that two substitutes scored the goals.
Nkoulou, the Lyon defender, started only once during the tournament and came on as a first-half replacement for the injured Adolphe Teikeu.
Aboubakar, the powerful centre-forward currently playing for Besiktas in Turkey, also started only one game in Gabon, but he had scored the decisive penalty in the shoot-out against Senegal in the last eight and his winner in the final was stunning.
"It is the best way to win a final. I think we took a bit of a blow to the back of the head in the first half but the substitutions changed the match in the second half," said the forward Clinton N'Jie.
Cameroon were the first African nation to make a major impression at the World Cup and for a long time were the leading footballing force on the continent, but those days had seemed behind them following recent struggles.
Their last Cup of Nations final appearance had been in 2008, when a side featuring Samuel Eto'o lost 1-0 to Egypt in Accra, Ghana.
Eto'o, now 35, was among the crowd in Libreville on Sunday and later tweeted: "Champions of Africa!! Today the Cup of Nations, tomorrow the Confed Cup!!!"
Cameroon will now represent Africa at the Confederations Cup in Russia in June, where they will be in a group with Chile, Australia and world champions Germany.
They have a crucial double header with Nigeria to come in August and September as they look to qualify for the 2018 World Cup and they will also host the next Cup of Nations in 2019.