In a medium saucepan over medium heat, melt the butter. Whisk in the apple cider vinegar, flour, brown sugar, cinnamon, nutmeg, salt, water, and eggs and turn the heat to medium-low and bring to a simmer, whisking frequently. Remove the mixture from the heat once the filling can coat the back of a spoon.
Let the mixture cool 15 minutes and pour the filling into the pre-baked crust. Bake 45-55 minutes until the filling is just set.
Let cool to room temperature before eating.
Notes
Make a meringue topping if you wanna add a little bit of height to your pie.
Perfect Pairing
Why not make another pie?[embed_recipe id='34514']