Preheat oven to 425* F. Line a baking sheet with parchment paper.
In a medium bowl, combine sugar, flour, baking powder, salt and spices. Mix.
Grate the cold butter and combine into the dry ingredients with your hands until there are no more clumps, like a pie crust or biscuits
In a separate bowl, combine the pumpkin puree, half and half, and egg until combined.
Add the wet ingredients to the dry ingredients and mix until just combined, being careful not to over-mix.
Prepare a clean counter, dusted with flour. Turn the dough onto the counter and form into a circle that is about 1 inch thick. Using a knife, cut the scones into 8 triangles.
Bake for 15 minutes or until golden brown. Allow to fully cool before icing.