Make a short crust from the flour, egg yolk, three tablespoons of water, baking powder and a pinch of salt. Wrap in foil and put in the fridge for an hour.
For the topping, put the grated cheese in a bowl. Finely dice the cooked ham and add to the cheese. Mix both together with the creme fraiche and 2 eggs and season well with salt and pepper.
Line a greased springform pan with the batter. Spread the cheese mixture on top and smooth it out. Bake at 200 degrees for 40 minutes.