Preheat oven to 350.
Lightly grease a brownie pan, or any other square pan, with cooking spray; set aside.
In a large mixing bowl sift together flour, baking powder, salt and cinnamon.
Stir in oats, brown sugar, lemon zest, and pecans; mix well.
Add in oil and apple juice; work it with your fingertips until mixture resembles coarse crumbs. If necessary, add more liquid.
Press 2 cups of the mixture into the bottom of the prepared pan.
Arrange apples over the mixture.
Sprinkle the remaining of the mixture evenly over apples.
Bake for 30 to 35 minutes, or until apples are tender and top is golden brown.
Cool on a wire rack.
Cut into squares and serve.