Boil sweet potatoes in a large pot until they are tender.
Drain and let them cool before peeling.
In a mixing bowl, mash the sweet potatoes until smooth.
Add in sugar, eggs, softened butter, and vanilla extract, mixing well.
In a separate bowl, mix melted butter, flour, brown sugar, pecans, and cinnamon.
This will be your crunchy topping.
Pour the sweet potato mixture into a greased casserole dish.
Spread it evenly for consistent texture.
Top with the pecan mixture, spreading it evenly over the sweet potato layer.
Bake in a preheated oven at 350°F for 30 minutes or until the top is golden brown.