Peel the carrots and grate them on the large holes of a box grater or use shredding disc on food processor (you should have about 1 1/4 cups of grated carrot).
In bowl of food processor, pulse together the flour, baking powder, salt, and pumpkin pie spice briefly to mix.
Add cubed cold butter to processor and pulse until mixture resemble pea-sized crumbs. (If you don’t have or want to use a food processor, cut butter into flour mixture with a pastry cutter or two knives.)
Transfer flour/butter mixture to medium bowl; add the toasted pecans and carrots to the bowl. Stir until incorporated.
In a medium bowl or liquid measuring cup, whisk together the egg, cream, vanilla, and sugar until well-combined. Make a well in the center of the dry ingredients and add the egg mixture; stir to incorporate the wet ingredients just until combined.
On a work surface or in the bowl, fold the dough over onto itself using floured hands or spatula to incorporate any dry floury patches.
Line a baking sheet with parchment paper; sprinkle a bit of flour on parchment paper.
Transfer the dough to the parchment. Use floured hands to pat into an 8 to 9-inch disc, about 1" thick. Place in the freezer for 30 minutes (this helps firm up the dough for cleaner cuts).
Using a bench scraper or knife, slice each circle into 8 wedges. Separate the pieces so that there is at least 1" between them. Brush the top of the scones with cream and sprinkle with coarse sparkling sugar.
Place the pan into oven preheated to 375°F. Bake, rotating the pan once halfway through, for 25 to 30 minutes, until the scones are golden brown.
Remove from the oven. Transfer scones to wire rack to cool. While the scones are cooling, prepare the glaze.