Preheat oven to 325°F (163°C). Coat a 9×5-inch loaf pan with solid vegetable shortening, followed by granulated sugar or Wilton Cake Release. (link above in equipment for cake release)
In the bowl of a stand mixer, or using a handheld mixer, beat the softened butter and sugar together at medium speed until light and fluffy, about 3 minutes. Stop the mixture and scrape the sides and bottom.
With the mixer running on low speed, add the eggs one at a time and beat until the yellow disappears into the batter. Stop the mixture and scrape the sides and bottom of the bowl.
While the mixture is creaming, combine the flour, baking powder, and salt in another bowl. After the eggs have been mixed in, turn to low and add this flour mixture slowly. Mix until just combined. Stop the mixer and scrape the sides and bottom of the bowl. Mix to combine. This batter is very thick. Don't overmix, especially after you've added the flour.
Spread ½ of the batter into the prepared loaf pan. Stir all of the Nutella into the remaining batter. Smooth the top.
Bake the pound cake for 50-60 minutes. Cover with aluminum foil after 30 minutes to avoid the top and sides from over-browning. The cake is done when a toothpick inserted in the center comes out clean or with dry cake crumbs. You can also test with a cake tester. I baked my cake for 55 minutes. Yours may take longer, so watch it closely for the last 20 minutes.
Allow the cake to cool for 20 minutes in the pan before inverting it on a wire rack to cool completely.
Store cake in an airtight container on the counter (or fridge if you prefer). It will start fresh for 6 to 7 days. If it begins to get a little stale, you can heat it in a pan and toast both sides. It's great served with vanilla ice cream.
Notes
Sift first, then measure the flour. Measure using the spoon & level method. Or, you can use a kitchen scale to measure by weight.