Rustic Southern Sweet Potato Pie

2 large yams
2 large sweet potatoes
2 cups sugar
1 stick butter (melted)
1 teaspoon cinnamon
1/2 teaspoon fresh ground nutmeg
1/2 teaspoon salt
1 teaspoon pure vanilla extract
3 tablespoons butter
3 cups flour
1/4 cup sugar
1/3 cup olive oil
1 teaspoon pure vanilla extract
1 cup whole milk
1 egg
1 tablespoon milk

In a large pot, boil yams and potatoes for about one hour or until tender. Drain water and let potatoes cool. When cool enough to handle, peel skins off and place yams and potatoes in a ricer or potato masher.

In a bowl, combine yams and potatoes, 2 cups of sugar, melted butter, 1 teaspoon cinnamon, 1/2 teaspoon nutmeg, 1/2 teaspoon salt and 1 teaspoon vanilla. Mix well.

Dough:
Heat oven to 375 degrees F. In a small saucepan, heat the butter until it turns golden brown. When done, it should have a nutty-like aroma. Remove from heat and let cool.

In a large bowl, combine 3 cups flour, 1/2 teaspoon salt and 1/4 cup sugar, mixing well.

In another bowl, whisk together 1/3 cup olive oil, 1 teaspoon vanilla extract, 1 cup milk and melted butter.

Pour into the flour mixture and mix with a fork. Dough should hold together. If too crumbly, add ice water, a tablespoon at a time. Cover and let sit for about a half an hour.

To Assemble:
On a floured surface, roll out dough to fit a 14-inch round or rectangular baking pan. Place dough on pan. Spoon filling into the center of the dough, leaving about a 1 1/2-inch border. Gently fold the sides of the dough up and over some of the filling.

Make an egg wash by mixing the egg and tablespoon of milk together with a fork. Coat the bread with egg wash using a pasty brush. Sprinkle with sugar. Bake for about 45 minutes or until crust is golden brown.

Serve alone or with vanilla ice cream or whipped cream.