Preheat the oven to 425 and line a baking sheet with parchment paper.
In a large bowl, combine flour, sugar, baking powder, salt and spices.
Using your hands or a pastry cutter, cut butter into the dry mix until it resembles a coarse meal; set aside
In another bowl, whisk together pumpkin, yogurt and egg.
Fold wet ingredients into dry and gently mix into a ball; don't overmix.
Pat dough out, gently, onto a floured surface and form into a rectangle 9" x 3"; slice lengthwise into 2 equal pieces and then cut each piece so you have 9 triangular pieces.
Meanwhile, get your glaze ingredients ready (just mix them all together in a bowl); set aside.
Instead of the triangle, you can just use a round cookie cutter and cut into rounds like this (the only thing with this method is re-rolling...this dough makes tough scones if you work it too much, so take the scraps and gently push the pieces together and cut more shapes; if you knead it, you will get pumpkin flavoured hockey pucks!).
Place them on a baking sheet with a bit of room between them (they get bigger but don't spread like a chocolate chip cookie!) and bake for 14 - 16 minutes.
Remove from the oven and let cool for a couple of minutes; drizzle the glaze onto each scone.