Preheat oven to 350° F.

Spray a 9×13-inch baking dish with non-stick cooking spray.  Set aside.

Sift together flour, baking powder, baking soda and salt into a large bowl. Set aside. 

In a large bowl of a stand mixer, combine butter, sugar and orange zest.  Beat at low-medium speed until creamy.  Add eggs, vanilla and beat again for 30 seconds. 

Add dry flour mixture gradually, alternating with sour cream. Mix until smooth. 

In a medium bowl, combine peaches, brown sugar, cinnamon and flour. Stir to coat peaches evenly.

Spread half the batter in prepared baking dish. Top with a layer of peach mixture, making sure peaches do not touch the sides of the dish. Spread remaining batter evenly over peaches.

For Streusel:

Combine flour, brown sugar and butter in a small bowl. Mix ingredients with your hand. Add pecans and continue mixing with hands.  Course crumbs will form.  Sprinkle streusel over cake.

Bake for 45 minutes or until when tested with a toothpick, toothpick comes out clean.  Cool in pan for 20 minutes.  Slice and serve.