Method

• 1.
  Grease a 15 cup (3.75L) bundt pan with butter. Dust with flour to coat evenly, shaking away excess. Chill until required.
• 2.
  For the caramelised apples, place butter, sugar and a good pinch of fine salt in a large frypan over low heat and cook, stirring, for 2 minutes or until butter melts and sugar has dissolved. Stir in cinnamon and nutmeg. Add apple, cut-side down, and cook for 1 minute until caramelised. Turn and cook for a further 2 minutes until caramelised. Transfer apple to a plate and set aside. Remove pan from the heat and cool butter mixture in pan. Pour cooled butter mixture into the prepared chilled bundt pan and tilt to cover evenly. Set aside.
• 3.
  Sift flour and baking powder into a bowl and set aside. Using a fork, lightly whisk whole eggs and egg yolks in a bowl. Set aside.
• 4.
  In the bowl of a stand mixer fitted with the paddle attachment, beat the butter, sugar, 1 tsp fine salt, vanilla seeds and extract and lemon zest on a medium speed for 10 minutes until pale and white. Reduce speed to the lowest setting. Slowly add the whisked eggs, stopping every minute or so to scrape down the sides of the bowl (this process should be slow, and mindfully done). Increase speed to medium and beat for 1 minute to fully incorporate the mixture. Add the ricotta, and mix into the cake batter on medium-low speed. Add half the sifted flour mixture. Mix on medium-low speed for 1-2 minutes. Repeat with remaining flour mixture (you don’t want to overmix, so you can keep a lovely light texture to the cake).
• 5.
  Using a rubber spatula, gently transfer the cake batter into a large bowl, gently stirring to incorporate any loose flour that may have accumulated in the bottom of the mixing bowl. Stand at room temperature for 1 hour or so. This will help loosen the batter so that you have a nice moist, soft cake rather than a dense one.
• 6.
  Preheat oven to 180°C/160°C fan-forced. Arrange apple slices in base of bundt pan, overlapping slightly. Spoon cake batter evenly over the apples, spreading to level the top and leaving a 3cm gap at the top of the pan for the cake to rise.
• 7.
  Bake for 50-55 minutes until just cooked when tested with a skewer. Transfer cake, in pan, to a wire rack and set aside for 1 hour to cool.
• 8.
  Turn cake, in pan, upside down onto a serving plate and set aside for 30 minutes to settle before lifting the pan off. Slightly pound the hazelnuts so they break but not too finely. Scatter hazelnuts evenly over the cake. Serve with ice cream alongside.