Karen says to combine the brown sugar, flour, dark corn syrup, vanilla and the beaten egg in a two-quart saucepan. Gradually stir in the cup of water.
Cook over medium heat until the mixture comes to a boil; set aside to cool. Pour this mixture into an unbaked 9-inch pie shell.
Mix together the crumb topping ingredients. You will find that using a pastry cutter will help you get nice, consistent-size crumbs. Sprinkle the crumbs over the filling in the pie pastry.
Bake in a preheated oven at 350 degrees for approximately 40 minutes. When cooled down, slice and serve.
Youíll probably need to bake a number of these pies to keep your dinner guests satisfied. If you have any doubts about how well you did baking such a pie, just give me a call and Iíll come give it a taste test to be sure you did it right.