Sour Cream-Sweet Potato Pie

Name: Sour Cream-Sweet Potato Pie
Prep time: 30 min
Total time: 30 min
Cuisine: American, Southern
Ingredients: 1 1/4 c. all-purpose flour; 1 tbsp. sugar; 1/4 tsp. salt; 1/2 stick cold unsalted butter; 3 tbsp. cold unsalted butter; 4 tbsp. cold lard; 1 c. light-brown sugar; 2 tbsp. all-purpose flour; 1/2 tsp. ground cinnamon; 1/4 tsp. grated nutmeg; 1/4 tsp. salt; 1/2 c. milk; 1/2 c. sour cream; 3 large eggs; 1 large egg yolk; 1 tsp. pure vanilla extract; 2 c. pureed cooked sweet potatoes