Preheat the oven to 350°F. Lightly grease a 9-inch pie plate.
In a large mixing bowl, whisk together the sugar, flour, baking powder, and salt.
Add in the melted butter, eggs, milk, pumpkin purée, pumpkin pie spice, and vanilla. Whisk until smooth and well combined.
Pour the mixture into the prepared pie plate.
Bake for 45–50 minutes or until the center is set and a knife inserted near the center comes out clean. The pie will puff slightly as it bakes, then settle as it cools.
Let cool completely on a wire rack. Serve at room temperature or chilled, with whipped cream if desired.
Video
Notes
Be sure to use pure pumpkin purée, not pumpkin pie filling.
The pie will puff up while baking and settle as it cools—this is normal.
Cool completely before slicing for neat pieces.
Store covered in the fridge for up to 4 days, or freeze for up to 2 months.