In a medium saucepan, heat cherries and water, stirring constantly. As cherries thaw, mash them with a spoon. Add 3/8 cup granulated sugar, and continue to stir.

Slowly add cornstarch, continuing to stir. Bring mixture to a light boil, and turn heat down to low. Stir until mixture thickens to the consistency of a thick jam.

Remove from heat, and allow to cool in a heatproof bowl. You can place it in the fridge if you need to speed up the process.

Unroll the filo dough. Place one sheet on a cutting board. Brush with melted butter, and sprinkle with 1-1/2 teaspoons sugar. Place another sheet directly on top, and repeat the process until you have three layers of dough, butter, and sugar.

Evenly place 2 Tablespoons of crumbled filo dough on the bottom 1/3 of the top layer of filo dough, leaving one inch around the bottom and sides free. Cover crumbled filo dough with ¼ cup cherry filling.

Fold bottom and sides in so the filling does not escape.

Gently fold strudel over twice so resulting pastry is roughly 6 inches x 2 inches.

Repeat the process to make a total of 3 strudel. Place on buttered cookie sheet. Brush the tops of each strudel with melted butter, and sprinkle each with ½ teaspoon sugar.

Use a sharp knife to cut 4, 1-inch slits in the top of each strudel, evenly spaced out. The slits should go through to the filling but not into the dough below the filling.

Bake at 400F on center oven rack for 15 minutes, or until golden brown and crispy. Strudel are best when served fresh, after being allowed to cool for 5-10 minutes.