In the second round of the grand finals, each of the four finalists must undertake the knowledge test - a series of difficult questions and practical challenges set by series judges Mary Berry and Paul Hollywood. Then they are tasked by presenter Aaron Craze with baking for a glamorous event - the fifth-anniversary party of the musical Wicked in London's West End. It's the first time the bakers have prepared food for a professional event and it's a chance to show their potential as expert caterers. The heat is on as this is the penultimate challenge before Mary and Paul decide who to award the title of Junior Bake Off champion. Show less