original recipe called for 1/4 cup more brown sugar - it was still quite sweet so the next time I make it, I'm only going to add 1/3 cup total. I put in the zest of an entire orange and added a splash of orange extract.
Instead of streusel topping, I made a glaze using approximately 1 cup powdered sugar and orange extract. After mixing it until smooth, I heated it in the microwave and drizzled it over the warm cake.