Place butter in freezer.
Preheat oven to 400° F (205° C).
While oven is preheating, measure remaining dry ingredients (flour, sugar, baking powder, and spices) into a medium sized bowl and stir to combine.
Place nuts on a baking sheet and toast in preheated oven for about 6 minutes until they start to smell roasted but aren't turning brown yet. Remove and set aside.
Remove butter from freezer and either cut into chunks using a knife or grate using the large holes in a cheese grater. Add to dry ingredients and work in with a pastry cutter or fork until butter is in small, pea-sized pieces.
Chop nuts and add to mixture.
Add pumpkin, milk, and vanilla and stir well or mix in using hands.
Place dough on a floured surface and use hands to press into a round 1 inch thick circle (dough will be sticky, but you can add a touch more flour if its too wet to work with).
Cut into eight triangles and place each on a lined or pre-greased cookie sheet.
Bake in preheated oven for 16 - 18 mins until scones are cooked through but not tough. Don't over bake or the scones will be dry!
While scones are baking, prepare icing by adding all glaze ingredients to a small bowl and using a wire whisk to mix in. If glaze is too runny, add more powdered sugar and if too thick to pour add a small amount more milk.
After removing scones from oven, allow to cool completely before drizzling each scone with glaze.