Best Apple Cobbler

I got this recipe from a country cookbook, all though it was originally "The Best Peach Cobbler" I have tweaked it and was able to use it for 5 different types of cobblers. It comes out perfect every time! I've made some pretty bad cobblers , wet and gooey on the bottom and hard and dry on top, but this comes out delicious every time. I think it is the boiling water that does the trick.
Ingredients
Filling
3 pounds tart apples (6 cups) (peeled, cored, sliced)
1/4 cup sugar
1 1/2 Tbsp all purpose flour
1/2 teaspoon cinnamon
4 Tbsp butter
3 Tbsp lemon juice
1 teaspoon vanilla
Crust
1 cup self rising flour (which is 1 cup all purp. flour minus 2 teaspoons of flour plus 1/2 teaspoon salt and 1 1/2 teaspoon baking powder)
1/2 cup milk
3/4 cup sugar
3 Tbsp butter (soft)
Sugar topping - 1/4 cup sugar, 1/8 teaspoon cinnamon, & 1/2 Tbsp cornstarch
*1 cup boiling water
Directions
Set oven to 350
Filling
Fry the apples along with the lemon juice, sugar, cinnamon, and flour in the butter (partially covered and stirring occasionally) for about 10 minutes (tender)
Crust
Pour apples into a well buttered square pan
Beat the sugar and butter, blend in the milk and flour and mix gently
Spread over fruit
Sugar Topping: Combine sugar and corn starch and sprinkle over batter
*Pour BOILING water over top
Bake for 1 hour (browned)
Allow to cool and set for atleast 20 minutes before serving....if you can!