1Heat oven to 350°F (325°F for dark or nonstick pan). In 13x9-inch pan, melt butter in oven. Place peach slices on paper towels to absorb liquid.
2In large bowl, mix cake mix, cinnamon, nutmeg, eggs and 3/4 cup reserved peach syrup with spoon until well blended. Drop batter by spoonfuls over butter in pan; spread slightly without stirring. Arrange peach slices over batter.
3Bake 25 minutes. Sprinkle evenly with pecans and sugar. Bake 13 to 18 minutes longer or until edges are deep golden brown and center springs back when touched lightly in center. Cool 30 minutes. Serve warm or cool.