Can I use fresh orange peels instead of candied orange peels?
No - fresh orange peels will make the cake very bitter. Omit the candied orange peels if you do not have them. But you can add orange zest - which is the orange colored part of a fresh orange peel. Use a grater or a zester, to get fine grates of the orange part of the peel and not the white part. You can add about 1 tablespoon of orange zest to the batter.