First, prepare your pie crust to the manufacturers instructions. I rolled mine out onto a 9-inch pie plate and poked holes all in it.
Be sure to use pie weights, otherwise the pie crust will shrink. Then, bake it for about 10 minutes before adding the filling in.
While the pie crust is baking, you can prepare your filling. In the bowl of an electric mixer, combine the apple butter, brown sugar, flour, eggs, and vanilla until it's a smooth filling and lump-free.
Add in the sweetened condensed milk and whisk again until smooth.
Bake at the center rack for 30 minutes, then move to the lower rack for an additional 20 minutes. If you notice your pie crust edges start to burn near the end, you can always cover it with some aluminum foil until it's finished baking.
You want the entire pie to be a nice golden brown color, but completely set in the middle. Let cool on a wire rack for 3 hours.
Then refrigerate to fully set before cutting and serving for best results. Serve with a dollop of whipped cream or even a scoop of vanilla ice cream with a sprinkle of cinnamon.
Store in an airtight container in the fridge for up to 3 days.
