Preheat oven to 350 degrees Fahrenheit.

Place raisins in a saucepan with a small amount of water.

Cook the raisins until they become plump, about 15-20 minutes.

Drain the plumped raisins and set aside.

In a mixing bowl, combine sugar, flour, melted butter, and eggs.

Beat the mixture until it is well blended and smooth.

Stir the drained raisins into the mixture.

Pour the raisin filling into the unbaked 9-inch pie crust.

Bake in the preheated oven for approximately 40 minutes.

Check for doneness; the pie should be firm to the touch.

Remove from oven and let cool before serving.