Nutella fans will rejoice in this easy, tangy cake, which incorporates sifted flour to ensure it's light. There's no real mystery to how it's made — just fill a silicone mold 3/4 of the way, top it with a Nutella-mascarpone filling and finish it with additional batter. Then, transfer it to the oven to bake, and enjoy the cake warm or once cooled — but definitely with a glass of milk or cup of hot tea.