1. Preparing the cake:

• Pre-heat oven to 175 degree Celsius.
• Beat 1 cup of sugar, butter, vanilla and cream cheese at medium speed in the Bosch kitchen machine for about 4 minutes.
• Add eggs one at a time.
• Combine flour, baking powder and salt. Sift them.
• Add the flour mixture to the cream mixture and beat at low speed until blended.
• Combine ¼ cup of sugar with cinnamon. Mix 2 tablespoons of cinnamon mixture and apple in a bowl and stir the apple mixture into the batter.
• Pour batter into pan lined with parchment paper. Place walnuts on batter and sprinkle remaining cinnamon mixture on top.
• Bake at 175 degree Celsius for 1 hour. Cover with aluminium foil after 20 minutes to prevent over-browning. Cool cake on rack.

2. Preparing the custard cream:

• Boil the milk and grated lemon zest.
• Beat egg yolks and castor sugar till white.
• Sieve cake flour and corn starch together. Divide into 7 portions and add each portion at a time into the whisked egg and sugar mixture. Mix well.
• Slowly add the milk into the egg mixture. Whisk to combine.
• Cook the custard over a double boiler and whisk constantly. Wrap and cool the mixture in the fridge.
• Whisk whipping cream and icing sugar till soft peaks form.
• Combine Kirsch with the whipped cream and custard mixture.