Pecan-Crusted Sweet Potatoes

3 cups peeled, cooked sweet potatoes (reserve cooking water) or 1 large can, drained (reserve juice).
2 eggs or 1/2 cup egg substitute
1/4 cup regular sugar, or more to taste
1/2 cup melted butter or Smart Balance
1 tsp vanilla
Scant 1/2 cup milk
1/2 cup flour to thicken (optional)
1/2 cup firmly packed brown sugar
3 Tbsp melted margarine
1/4 cup flour, sifted if possible
1/2 cup finely chopped pecans

Mash potatoes with a little juice from can or cooking water. Add all ingredients except those for the topping (brown sugar, 3 Tbsp margarine, flour, and pecans). If it is too soft and soupy, add 1/2 cup flour, a little at a time. You want it very soft, but not so soft that the topping sinks into the potatoes. Spread into a 4-6 cup pan and smooth out the top. It will be a little lumpy. Combine topping ingredients. Feel free to make extra if you like the topping a lot. Drop by spoonfuls on top of the potatoes. Bake at 350⁰ for 25 to 30 minutes, or until set.