To a large microwave safe bowl, add the water, butter, and milk. Heat until the mixture is in the range of 95-110 degrees F. If it is hotter, allow it to cool to that range before proceeding. Alternatively, you can do this step in a saucepan over medium-high heat on the stove.
To a large mixing bowl, or the bowl of your stand mixer, whisk together 3 1/2 cups of the flour, salt, sugar and instant yeast.
Add the warm liquid mixture to the flour mixture and knead for 6-8 minutes until a soft ball forms and pulls clean away from the sides of the bowl. Add the additional 1 cup flour, as needed.
Place the dough in a greased bowl and cover with plastic wrap and a clean towel for 15 minutes.
Spray a 9” x 13” casserole dish with non-stick spray and set aside.
After 15 minutes, punch down the dough and divide into 12-15 equal sized balls of dough.
Place the balls of dough in the greased casserole dish and re-cover with plastic wrap and towel for another 15 minutes.
Preheat your oven to 400F.
Remove plastic wrap and towel from the casserole dish and place the dish in the oven for 15 minutes, until puffed and golden brown on top.
If brushing with butter, brush halfway through baking with 1 tablespoon of melted butter and then again after baking.
Store leftovers covered for up to 5 days.You can freeze baked rolls, wrapped tightly in a freezer bag, for up to 3 months.