Bourbon Sweet Potato Casserole

Preheat the oven to 350 degrees F. Start by making the streusel. Combine melted butter, chopped pecans, brown sugar, flour, cinnamon, and nutmeg, and the tiniest pinch of salt in a medium bowl. Mix together until crumbly and add to the refrigerator.
Peel and cut sweet potatoes in half (this will allow them to boil quicker). Bring a large pot of water to a boil and add about 1-1 1/2 tablespoons of kosher salt to the water. Boil sweet potatoes until fork tender then drain them and add to a large bowl.
Mash the sweet potatoes and add the butter, brown sugar, ground cinnamon,ground nutmeg, ground ginger, maple syrup, and evaporated milk. Mash everything together until you get a nice smooth consistency. Then add vanilla extract, bourbon, and an egg. Continue to mix together until all of the ingredients are combined.
Spray a 9x13 casserole dish with cooking spray and add the sweet potato mixture to the prepared baking dish. Add the pecan mixture on top of the sweet potatoes and bake in the oven for 1 hour.