The best chocolate chip cookies

1 cup butter, melted
2 cups brown sugar
2 eggs
2 2/3 cups all-purpose flour
1 teaspoon baking powder
1 teaspoon baking soda
1 teaspoon vanilla
2 cups semisweet chocolate chips

Preheat the oven to 375 degrees F. In a medium bowl, stir together the melted butter and brown sugar until smooth. Beat in the eggs one at a time. Add the vanilla. Combine the flour, baking powder and baking soda, gradually stir into the sugar mixture. Fold in the chocolate chips. Arrange sparsely on ungreased cookie sheets. Bake for 8 to 10 minutes.