In a large mixing bowl, add your flour, brown sugar, baking powder, pumpkin pie spice, and salt and whisk together till combined.
To another bowl, add your pumpkin puree, milk and egg and whisk together till smooth.
On a cutting board, cut your butter into small, pea-sized chunks and add them to your bowl of dry ingredients. Stir them into your dry ingredients, till they're well incorporated.
Pour your wet ingredients over your dry ingredients and mix till you have a shaggy dough (it will still be a little crumbly).
Put a piece of parchment paper on your counter. Dump the scone dough onto the parchment paper and work the dough lightly till you can form a smooth disc shape (about an 1-1 1/2 inches tall). Carefully move the parchment paper (and scone dough disc) onto a pan.
Use a large, sharp knife, and cut the scones into either 6 or 8 wedges (I prefer 6 large scones). Using a spatula, gently move the scones so they are 1-2 inches apart on the pan. Place in the fridge for 15 minutes.
Preheat your oven to 400.
Bake the scones in the oven for 15-17 minutes, or till the top is fairly solid to touch (not mushy) and a toothpick inserted comes out clean.
To a small bowl, add your powdered sugar and cocoa powder and whisk them together till well combined. Add your milk and vanilla and whisk till you have a very thick glaze. If you would like it to be thinner, you can keep adding 1-2 tsp's of milk till it reaches your desired consistency.
Pipe (or drizzle, if thinner) on top of your cooled or warm (not hot!) scones. Devour!
Stored in an airtight container at room temperature these taste best within 1-2 days. Or, store them in the fridge for about a week.