Spring Fruits Pie

I have never really seen the point of the "Fruits of the Forest" pie.  It might just be that I hate all pies that aren't homemade (frozen and store-bought aren't really my thing) and fruits of the forest was not one that I had ever had.  Frankly, the concept of apples with berries sounded sort of gross. There is a story behind how I then ended up making one; a story that involves me thinking I had much more rhubarb than I really had and stupid already having measured all the dry ingredients for pie filling into the mixing bowl.  Apples are tart and I had some, so that's what ended up in this pie.  The pie has a very pretty color and a fantastic flavor.

Makes 9-inch pie

Crust for double-crust pie
3/4 cup sugar
1/4 cup flour
Dash cinnamon
1/2 cup diced rhubarb
1 cup sliced strawberries
3 Granny Smith apples, sliced into bite-sized pieces
Sugar, for sprinkling

1. Preheat oven to 375 degrees.
2. In large mixing bowl, mix sugar and flour.  Stir in cinnamon.  Toss all fruits with with the sugar mixture and set aside.
3. Usually I let the fruit filling sit while I make the crusts.  The fruits in the filling will release juices and the flour will start to thicken it as it sits. 
4. Roll out the bottom crust and fit it to the pie plate. Stir the fruit filling and pour it into the lined pie plate.  Roll out top crust, cut a vent, and place it over the fruit filling.  Seal the edges and flute them as you desire.  Sprinkle the top crust with a fine layer of sugar to help it brown.
5. Bake pie in oven for 40-45 minutes or until the crust is golden and the filling bubbles out of the vent.  Remove pie to cooling rack.  Serve warm of cooled.