Whipped Sweet Potatoes

I made this for Thanksgiving this year.  I had to leave out the pecans because of a potential allergy with one of my guests.  We did not even miss them and the dish was a big hit.

Topping
1 1/3 C Cornflakes, crushed
½ C packed brown sugar
½ C pecans, chopped (optional)
5 T butter, melted

Potatoes
2 large sweet potatoes, cut into 1-inch pieces
4 T butter, softened
6 T sugar
1 egg
3/4 t ground cinnamon
1/2 t ground ginger
1/2 t ground cloves
1/8 tsp salt

Boil potatoes for 15 minutes, until tender; drain well.  Beat potatoes and butter until smooth.  Add remaining ingredients and beat.  Spoon into an 8 x 8-inch baking dish.  Bake at 400F for 25 minutes until edges are brown and slightly puffed.  Sprinkle with topping and bake until golden and crisp (5 more minutes).