Line 2 baking sheets with parchment paper.
Spray another baking sheet with nonstick spray. Divide the Nutella into ½-teaspoon-sized balls and place the balls on the sprayed baking sheet. Be sure they aren’t touching. Freeze for at least 30 minutes.
¼-½ cup Nutella
Chop the pecans in a food processor until fine. Don’t process too much or the nuts will turn oily. Set aside. (If a food processor isn’t available, place the pecans in a resealable bag and roll or pound until the nuts are finely chopped.)
¾ cup very finely chopped or ground pecans
In the bowl of a stand mixer, beat the butter and ½ cup powdered sugar on medium-high speed until the mixture is light. Add in the vanilla extract, salt, and ground pecans.
8½ tablespoons unsalted butter, 1½ cups powdered sugar, ½ teaspoon pure vanilla extract, ¼ teaspoon kosher salt
Add the flour and mix on low speed until the flour has been incorporated. Roll the dough onto a clean work surface and knead gently for 30 seconds. Form the dough into a ball, cover loosely with plastic wrap, press gently to flatten into a disc, and place in the refrigerator for 30 minutes to firm up.
1¼ cups all-purpose flour
Preheat oven to 375°F.
Remove the Nutella balls and cookie dough from the fridge. (If the Nutella balls start to soften, place them in the freezer for a few minutes.) Pinch off a 2-inch piece of the dough and divide it in half. Slightly flatten one half in the palm of your hand and place a Nutella ball in the middle of the dough. Top it with the other dough half and wrap the 2 sides together around the Nutella ball. Gently roll the cookie in your hands to seal the edges and to form a ball. Place the cookie ball on a parchment-lined cookie sheet, 2 inches apart, and repeat until all cookies are made.
Place the trays of cookies in the refrigerator for 30 minutes.
After 30 minutes, place the cookies in the hot oven and bake 14-16 minutes or until they are light golden brown and firm to the touch. Remove from the oven and let rest 3 minutes on the baking sheet.
Place ½ cup powdered sugar in a bowl and roll the warm cookies, one-at-a-time, in the sugar. Return them to the still-hot baking sheet to cool another 5 minutes. Roll the cookies with a second coating of powdered sugar. Allow to completely dry.
If a third coat of powdered sugar is desired, place powdered sugar in a small wire sieve and sprinkle it over the cookies.