Sixteen teenagers have gotten an unexpected opportunity to confess sins to Pope Francis.

The pontiff made a surprise appearance late Saturday morning in St. Peter’s Square, where thousands of Catholics faithful, ranging in age from 13 to 16, were participating in a special Holy Year youth day, including confession near the famed Colonnade of Bernini.

Francis and each of the 16 teenagers sat face-to-face in simple chairs set up in pairs for him and many others hearing confessions in the square. The teenagers seemed at ease, with Francis shaking hands warmly with the youths. In all, the pope spent more than an hour in the square.

He has dedicated the Holy Year to two central themes of his papacy: mercy and reconciliation.

Roughly 70,000 young people, mostly from Italy but also other parts of the world, were expected to take part in the youth gathering under the title “Growing merciful like the Father.” The event concludes on Monday.

Some 150 priests have been deployed in St. Peter’s Square during the days of the gather to hear confessions from 9:30 a.m. to 5:30 p.m. Attempting to promote reception of the sacrament of reconciliation has been a hallmark of Francis’ papacy.

Saturday is also the Catholic feast of St. George, the namesake of the pontiff, whose given name is Jorge Mario Bergoglio. On the occasion, the Vatican kitchens presented the pontiff with an enormous cake, made with organic nuts from Viterbo and fine pistachios.

The cask also carried a design of St. George, the 3rd century Christian martyr, depicting him in a horseman’s outfit as he prepares to slay the legendary dragon.

According to Italian media reports, the cake was made based on a special glycemic recipe to respect the pope’s dietary requirements. It was prepared by a pastry shop called “Hedera” located on Rome’s Borgo Pio, just steps away from St. Peter’s Square, which often is called upon to bake for popes on social occasions.