You can use any type of plum for this pie so long as the plums are not too hard and not too soft. (Too hard and they won’t cook down nicely; too soft and you’ll end up with goo instead of soft slices of plum.)

Steps

1. Make the crust: Using a box grater with large holes, grate the butter into small pea-sized bits. Mix quickly by hand with the flour, salt, and sugar. (Alternatively, blend the dry ingredients with the flour using a pastry blender or a few quick pulses of a food processor.) Dribble in the ice water, a tablespoon at a time, until the dough is just wet enough to hold together. Form the dough into two disks, wrap each disk in plastic wrap, and chill for 30 minutes (or freeze for 10 minutes) before rolling out.
2. Preheat the oven to 375 degrees. Mix together the filling ingredients, making sure that the flour is dissolved.
3. On a floured board with a floured rolling pin, roll out the first disk of dough and lay it across the bottom of a large pie plate. Pour the filling into the dough. Roll out the second disk of dough and lay it across the top of the pie, crimping it shut evenly around the edges and piercing the top crust several times with a knife or fork.
4. Bake for 60 minutes (you may wish to use a baking sheet underneath the pie to catch any juices that bubble out) until nicely browned on top. Serve warm with ice cream or at room temperature.