Preheat oven to 350 degrees F (175 degrees C). Grease one 9-inch pie pan, and set aside.

Sift together the flour, baking powder, salt, cinnamon, allspice, ginger and nutmeg.

In a large bowl, beat together the sugar, butter and eggs. Mix in the pumpkin, milk and vanilla. Add the sifted ingredients, and beat until smooth. Pour into the prepared pan.

Bake at 350 degrees F (175 degrees C) for 50 to 55 minutes, or until a toothpick inserted in center comes out clean.