Preheat oven to 425 degrees F. Grease pie plate and set aside.
In large bowl, beat eggs slightly; mix in remaining ingredients.
Place pie plate on oven rack; pour in filling. (I almost never do this latter step, but it makes sense. Personally, I’m in the “hum” or “count as you carry the pie to the oven” school of thinking to ensure the pie plate contents do not spill. Hey, it works for me!)
Reduce oven temperature to 350 degrees F. Bake until knife or toothpick comes out clean, about 45 minutes longer.
Flax “eggs” (or other egg substitutes that you have used successfully in custard pies) can be substituted for the chicken eggs for an egg-free, vegan version of this pie. The pumpkin butter already contains spices, so it's up to you if you want to add additional spices to your pie filling. I tried it both ways and liked both, but adding the spices in the filling definitely makes for a pretty spicy pie.
Recipe by gfe--gluten free easily at http://glutenfreeeasily.com/pumpkin-butter-pie-and-15-more-amazing-pumpkin-pie-recipe-solutions/