Step 1Combine flour, brown sugar and cinnamon in small bowl. Rub in butter to make mixture crumbly, then stir in nuts. Set aside.
Step 1Peel peaches using vegetable peeler or blanch in hot water 15 seconds and remove peel. Cut in half, remove pits and cut into 1/2-inch slices.
Step 2Stir together flour, baking powder and salt in medium bowl. Set aside.
Step 3Combine butter, shortening and sugar in large bowl; beat with hand-held electric mixer or wooden spoon until fluffy, 1 to 2 minutes. Beat in eggs, 1 at a time, then zest. Beat in flour mixture alternately with milk and vanilla, about one-fourth at a time, beginning and ending with flour. Batter will be thick and fluffy.
Step 4Combine brown sugar and cinnamon in small bowl. Spread half batter evenly in thin layer in greased and floured 13x9-inch cake pan. Arrange all of peach slices over batter and sprinkle with brown sugar mixture. Carefully spread remaining batter evenly over peaches. Crumble reserved Nut Topping over batter. Bake at 350 degrees in center of oven until toothpick inserted near center comes out clean and edges of cake barely begin to pull away from sides of pan, about 40 minutes.
Step 5Cool in pan on rack. Cut into squares and serve warm or at room temperature, directly from pan.