To make the donuts, in a large mixing bowl beat butter with a mixer on medium speed for 30 seconds. Add the sugar, baking powder, salt, baking soda and pumpkin pie spice. Beaut until combined, scraping down the the sides of the bowl as necessary. Beat in canned pumpkin, sour cream, egg, egg yolk and vanilla until combined. Stir in flour with rubber or wooden spatula until well combined. Cover with plastic wrap and chill for 3 hours.

Once chilled, on a well-floured surface, roll the dough to a 1/2 inch thickness. Cut with floured 2 1/2 inch dough cutter, dipping the cutter into flour between cuts. Re-roll as necessary.

Once the dough is cut and ready, prepare the glaze. In a large bowl using an electric mixer, beat the powdered sugar, corn syrup, salt, pumpkin pie spice, pumpkin puree and vanilla on medium speed until combined. Gradually add the hot water, scraping down the sides as necessary. Set aside.

Heat 2 inches of the oil to 325°F in a large and deep pot/pan. Place 2 or 3 donuts in the oil and allow to float to the top. Let cook for 20-30 seconds, then using the slotted spoon, flip over and allow to cook on the other side for another minute. Remove from oil and place on paper towel lined cooling rack to drain.

While the donuts are still hot, give the glaze a whisk and dip the cracked side of the donuts into the glaze. Let dry on cooking racks until set, about 10-15 minutes. Serve slightly warm. Donuts should be served the same day.