Step 1

Preheat oven to 160°C. Grease a 22cm springform cake pan. Place butter in a saucepan over medium heat and melt for 4-5 minutes, swirling the pan, until nutty brown. Place in a bowl to cool slightly.

Step 2

Place brioche in a food processor and whiz until finely chopped. Remove from processor and place in a bowl. Place shortbread in the processor and whiz until fine crumbs. Place in a bowl with the brioche and pour over the brown butter. Stir to combine. Press evenly into the base and side of prepared pan. Chill until needed. Wipe out food processor.

Step 3

Place cream cheese in processor and whiz until smooth. Add sour cream and whiz to combine. Add eggs and caster sugar and whiz to combine. Pour into pan. Combine cinnamon and demerara sugar in a bowl and scatter over the entire top of the cake. Place cake on a tray and bake for 1 hour 10 minutes or until just set with a gentle wobble in the centre. Turn off the oven and cool completely in the oven, then chill for 4 hours or until firm and set. Cut into slices and serve.