In a large bowl (or in the bowl of a stand mixer), place the softened butter, powdered sugar, vanilla, and orange zest. Using a hand mixer or stand mixer fitted with a paddle attachment, beat on medium speed until light and fluffy, 2 to 3 minutes. Add the cinnamon and flour and mix on low speed until just combined. Add the pecans and mix on low speed until just combined, scraping the bottom and sides of the bowl as needed.
Preheat the oven to 325°F. Position one oven rack in the top one-third of the oven, and the other rack in the bottom one-third of the oven.
Shape slightly mounded tablespoonfuls of dough into oval-shaped logs, about 2 ½ inches long. Place them on two baking sheets, about 2 inches apart and curve them into half circles.
Bake, rotating the baking sheets from the upper rack to the lower rack halfway through, just until the bottoms of the cookies are lightly golden, 20 to 22 minutes. Let cool on the baking sheet for 10 minutes before transferring to a bowl of powdered sugar. Dredge them while they are warm, then transfer to a cooling rack set over a baking sheet to cool completely. Once cool, sprinkle with additional powdered sugar, if desired. Store the cookies between layers of parchment paper in an air-tight container at room temperature for up to 1 week.
