Southern Sweet Potato Casserole

INGREDIENTS

6 lb

medium Garnet sweet potatoes

3/4 cup

packed dark brown sugar

3/4 cup

all-purpose flour

1/3 cup

old fashioned oats

1 tsp

kosher salt

7 tbsp

cold unsalted butter (, cut into 14 pieces)

1 cup

pecan halves (, finely chopped)

1/4 cup

plus 2 tablespoons bourbon

6 tbsp

unsalted butter ((3/4 stick), plus more for buttering the dish)

2 tsp

finely grated orange zest ((from 1 medium orange))

1 1/2 tsp

kosher salt

1 tsp

ground cinnamon

3/4 tsp

freshly grated nutmeg

1/4 cup

whole milk