Use fresh cherries and good Kirsch!
To Make Dough: Cream the confectioners' sugar and 3 eggs together in a large bowl. Stir in the orange flower water. Add the butter or margarine, and mix well. Slowly add the cake flour, blending only to combine. Scrape onto a piece of plastic, and wrap. Chill for at least 1 hour. Roll dough out on a floured surface, and fit into a 11 inch tart pan. Make sure there are no holes in the dough.
Place the cherries into the tart shell. Fit as many as you can in in one layer.
To Make Filling: Using a mixer, cream together the 3 eggs, 1/4 cup flour, kirsch, cream, and white sugar until smooth. Pour over the cherries.
Bake at 350 degrees F (175 degrees C) for about 40 minutes, or until the filling is just set. Allow to cool. Serve warm or at room temperature.