Lightly butter the cake pan and line with parchment paper.
Melt the butter, add to the crushed biscuits and brown
sugar, and mix.
Press the crust evenly in the bottom of the pan.
Combine cream cheese, 3/4 sugar and salt and mix on a medium speed with the paddle attachment until smooth around 3 minutes.
Whisk the egg and egg yolk and rest of sugar together, until foamy . Add the eggs to the cream cheese mixture in 4 additions.
Add heavy cream and vanilla and mix till fully incorporated.
Bake in hot water bath at 160°C until the center of the cake is set, about 2 hours.
Cool completely in the pan. Wrap with plastic and place in fridge.