Preheat oven to 350 degrees F (175 degrees C). Grease a 9x13 inch baking dish.
In a medium bowl, cream together the butter, brown sugar and vanilla until smooth. Combine the flour, baking powder, baking soda and salt; stir into the butter mixture until blended. Press half of the dough into the prepared pan.
In a large bowl, mix together the granulated sugar, cornstarch and cinnamon. Add apples and toss to coat. Spread evenly over crust in pan.
Crumble remaining dough over top of apple filling. Bake in preheated oven for 35 to 40 minutes, or until golden brown.