Preheat the oven to 400°F, and prepare the pie crust by placing it in a 9-inch pie plate. Trim and crimp the edges, and refrigerate until ready to use.
9- inch unbaked pie shell
Using a large bowl and electric mixer, combine the apple butter and eggs on low speed until well combined.
1 ½ cups (270 g) apple butter, 3 large eggs
Pour in the sweetened condensed milk, and beat on low speed until smooth. Add the brown sugar, vanilla, cinnamon, allspice, and salt. Continue mixing until everything is well mixed then pour into the prepared pie shell.
14 ounces (396 g) sweetened condensed milk, ¼ cup (50 g) dark brown sugar, 1 teaspoon vanilla extract, 1 teaspoon ground cinnamon, ½ teaspoon ground allspice, Pinch of salt
Bake at 400°F for 15 minutes. Then, decrease to 350°F, and bake for an additional 30-40 minutes. The pie is finished when the edges puff up and appear set. The center will look shiny, maybe a little wet, and it will jiggle slightly.
Remove the pie from the oven and let it cool for an hour at room temperature before transferring it to the fridge to set completely, about 3-4 hours.
Top with whipped cream, apple shaped pie crust cutouts, or a dusting of ground cinnamon. Serve chilled.
Notes
*The calories listed are an approximation based on the ingredients in the recipe card and a serving size of 1 slice assuming the pie is cut into 8 equal slices. Actual calories will vary.*For more information, tips, and answers to frequently asked questions, please refer to the post.*Adjust the amount of brown sugar if your apple butter is very sweet or not sweet enough. Just keep in mind that the sweetened condensed milk will also add some sweetness.