Combine flour, baking powder and salt; mix well and set aside. Combine agave, butter, milk, egg and orange peel in large mixing bowl; beat well. Add flour mixture, beating until smooth; stir in nuts. Pour batter into greased and floured 9 x 5 x 3-inch pan. Bake at 350°F for 50 to 60 minutes or until wooden pick inserted in center comes out clean; cool 10 minutes. Remove from pan and cool completely on wire rack.