In a large bowl or stand mixer, combine yeast, warm water, and 1 tablespoon sugar. You want the water to be nice and warm but not hot. Let the mixture sit for about 5-10 minutes and make sure it's nice and foamy. (If it's not, abandon ship!! You've killed your yeast. Toss it out and start over; this time make sure your water's not too hot.

Fill a 3-quart pot with water, cover, and bring to a boil over high heat.

In another medium bowl, combine salt, baking powder, 1/2 cup sugar, and bread flour. Set aside.

When the yeast is foamy, add the shortening, 3 egg yolks, and vanilla and stir with a wooden spoon.

Add about half the flour mixture and combine well with the spoon.

Attach the dough hook to the mixer, if using (if not, just use the spoon) Add the remaining flour mixture and stir well. Once all the flour is mixed in, knead with the dough hook for 2 minutes. Or knead by hand for 2 minutes on a floured surface. The dough should clean the sides of the bowl, it is not very sticky. See photos. Add more flour if necessary (I've never had to.)

Grease a large bowl with nonstick spray or rub with a little bit of oil. Shape the dough into a ball and place in the bowl. Turn it over so that the top is greased. Cover loosely with a tea towel or plastic wrap. Place on the top rack of your oven.

Place a 9x13 inch pan on the bottom rack. Carefully pour the boiling water into the pan. Close the oven door and don't open it again for 1 hour!

After one hour the dough should have doubled in size.

Pour the water from the pan back into the pot, cover, and bring to a boil again.

Line 2 large baking sheets with parchment paper or silpats. Spray with nonstick spray.

Punch down the dough and knead it a couple times on a lightly floured surface.

Use a rolling pin to roll the dough into a circle about 12x12 inches. The dough should be about half the thickness of your thumb.

Use a 2 and 1/2 inch biscuit cutter to cut the dough into doughnuts. Do not twist the cutter, push straight down.

Line up the doughnuts on the prepared baking sheets with plenty of space for them to rise. I was able to fit between 12-15 on each pan.

Place the pans in your oven. I only have two racks, and one pan fits on each, so I put the baking sheets on the racks and the dish of water directly on the floor of the oven.

Pour the boiling water back into the 9x13 inch dish, and place underneath the donuts.

Do not cover the donuts with a tea towel this time. Let rise in the oven for another 45 minutes, until doubled in size.

About 20 minutes before the doughnuts finish rising, start heating up the oil. It takes a while for the oil to heat up, so don't wait until the last minute, or your doughnuts might rise too high and then fall before the oil is hot enough.

In a high sided skillet, add 1 and 1/2 to 2 inches of oil. Turn the heat to medium. If you have a candy thermometer, attach it to the side of your pan. Heat the oil to between 360-370 degrees F. If you don't have a candy thermometer, after 15 minutes test a tiny piece of dough. If it starts bubbling right away, the oil is ready. You may have to adjust the heat a little bit lower than medium, depending on how powerful your burner is.

Line your counter with lots of paper towels, or better yet, a deconstructed clean paper grocery bag (they absorb more oil than paper towels.)

Add about 1 and 1/2 cups sugar to a pie plate or shallow bowl. Set a cooling rack nearby.

Use a large spatula to gently lift the donuts one at a time into the hot oil. I usually fry 3-4 at a time, but this depends on how big your pan is.

Let the donuts fry on one side for about a 30-45 seconds, until golden brown. Be careful, they will continue to darken as you remove them from the oil.

Use tongs to flip each donut, and fry for another 20-30 seconds. You will have to use your judgment here, especially if you don't have a candy thermometer. You don't want to end up with doughy-centered donuts.

Remove the donuts to the lined countertop. Wait for them to cool for just 15 seconds or so (enough to get another batch in the oil) and then roll them in the sugar. Don't be stingy! Pile it on! Remove the donuts to the cooling rack.

Finish with the remaining donuts.

When the donuts are still warm but cool enough to handle, use a couple toothpicks to poke a hole in the side of each donut. Work the toothpicks around a little bit inside the donut to create space for the filling.

Fill a pastry bag with Nutella. I used tip 1A, but just use what you have. Or fill a ziplock bag and snip off the end. You can also use a condiment bottle to fill the donuts.

Shove the pastry bag into the hole of the donut and fill until the donut starts to feel plump. Don't go overboard or it will just ooze out. Continue with the rest of the donuts, you may have to refill the pastry bag.

When all the donuts have been filled, top each donut with a dollop of Nutella. This is optional, and be aware that the Nutella has a hard time sticking to the sugar on the outside of the donut. It tends to slide off. I did it mostly for the photos, but then I realized that it actually is nice to have a little extra Nutella to spread around to the edges of the donut that didn't get filled as much. 

Eat these with a fork! Or go all heathen and use your hands. Eat warm! With lots of milk! Warm them up in the microwave for just about 10-15 seconds if you are eating them later.

To store, line several large tupperwares with paper towels. Store covered on the counter for a couple days. These are best eaten on day 1, but are still really good on day 2. I have no idea after than because they were gone!

Once the remaining oil in the pan has cooled completely, transfer it back to the original bottle so that you can use it again next time. (Get someone to help you.) Place the oil bottle in the sink, place a funnel on top, and place a mesh strainer on top of the funnel to catch any dough bits. Pour the oil from the pan through the strainer and funnel back into the bottle. Label your bottle so that you know the oil should only be used for frying.