Start the oven with electrical heat at 180 degrees Celsius.
Put the gingerbread cookies and the graham biscuits in a food blender and smash them into small crumbles.
Melt the butter and mix it together with the cookie crumbles.
Pour the mixture in a baking form with removable edges. Press the cookies like a pie bottom and press the cookies half up the edges.
Place the baking form in the middle of the oven for ten minutes.
During the time the bottom is in the oven continue with the filling.
Pour the cream Cheese in a bowl and stir it soft with an electrical mixer.
Pour the condensed milk, eggs and the citron juice in the bowl and stir gently while adding the ingredients.
Take out the cake bottom from the oven and pour in the filling.
Lower the heat on the oven to 160 degrees Celsius, and place the cake in the middle of the oven for another forty minutes.
Take out the cheesecake from the oven and let it rest one day before serving it.