Preheat oven to 350° F.
In a large bowl, mix together pumpkin purée, brown sugar, cinnamon, ginger, nutmeg, cloves, allspice, and salt.
Stir in maple syrup, half-and-half, and flour.
Mix in eggs one at a time.
Pour filling into unbaked pie shell.
Bake in middle of oven at 350° F for 1 hour, or until center is set.