Best Peach Cobbler EVER!

I had a request for this recipe from my sister in law, Charity. It really is the best peach cobbler. It's my Grandma's recipe. I think you all should try it!

2 lbs Peaches, peeled and sliced. Place in 9x13 baking dish.

Cream together: 2 sticks butter or margarine and 1 cup sugar.
Add:
1 cup milk
2 cups flour
2 tsp. baking powder
1/2 tsp. salt
1 tsp vanilla
Pour the batter over fruit.

1 cup brown sugar, 1/4 cup water.....mix and pour over dough

Bake at 350* for 1 hour.