Whisk first 8 ingredients in medium size bowl to blend. Using electric mixer, mix in sugar and butter in large bowl until blended (mixture will be grainy).
Beat in egg and vanilla, gradually mixing in buttermilk, add in pumpkin or sweet potatoes in 2 additions.
Using rubber spatula, fold in dry ingredients in 2 additions, blending gently after each addition.
Cover with plastic; chill 3 hours.
The dough will look very soft, must be cold to work with it. Dust your hands with flour to start working with the dough after it has been chilled.
Sprinkle 2 rimmed baking sheets lightly with flour. Press out 1/3 of dough on floured surface to 1/2 to 2/3-inch thickness.
Using 2 1/2-inch-diameter round cutter, cut out dough rounds and arrange on sheets. Repeat with remaining dough in 2 more batches.
Gather dough scraps. Press out dough and cut out more dough rounds until all dough is used.
Using 1-inch-diameter round cutter, cut out the center of each dough round to make doughnuts and doughnut holes.
Line 2 baking sheets with several layers of paper towels.
Pour oil into large deep skillet to depth of 1 1/2 inches.
Attach deep-fry thermometer and heat oil to 365°F to 370°F. If you do not have a thermometer test the oil with a bit of dough and see if the temperature is right. If the dough is too dark within seconds reduce the temperature.
Doughnuts should be golden brown on both sides.
Fry doughnut holes in 2 batches until golden brown, turning occasionally, about 2 minutes.
Using a slotted spoon, transfer the donut holes to the paper towels to drain.
Fry donuts, 3 or 4 at a time until golden brown, adjusting heat to maintain temperature, about 1 minute per side. Continue using the slotted spoon, transferring donuts holes to the paper towels to drain. Cool completely.
Donuts are dusted with cinnamon and sugar,
- 1 cup sugar
- 4 teaspoons ground cinnamon
- 2 teaspoons ground nutmeg ( optional )
Whisk all ingredients in medium size bowl to blend.
For powdered sugar
Dust powder sugar over donuts with a strainer.
You can mix spices with powder sugar according to taste.