
Preheat the oven to 350℉. Great a 9"x13" glass Pyrex casserole dish.
In the bowl of a large standing electric mixer, combine the sweet potatoes, sugar, room temp butter, milk, eggs, and vanilla. Mix until well blended. There may be some potato lumps, but that's okay. Spoon the potato mixture into the glass Pyrex casserole dish.
In the bowl of a food processor, combine the 3/8 cup butter, flour, pecans, coconut, and brown sugar. Process until the mixture is crumbly. Pour this topping on top of the casserole, making sure the potatoes are evenly covered.
Bake for 30 minutes, making sure the topping doesn't burn. Serve immediately.