Preheat your oven to 350°F (175°C). Line two large baking sheets with parchment paper or silicone mats. Set aside.

In a large mixing bowl, cream together the softened butter and the ½ cup of powdered sugar using an electric mixer until the mixture is light and fluffy (about 2 to 3 minutes). Beat in the vanilla extract.

In a separate medium bowl, whisk together the all-purpose flour and salt. Gradually add the flour mixture to the wet ingredients, mixing on low speed until the dough just comes together. Do not overmix.

Gently fold the finely chopped nuts (if using) into the dough until evenly distributed. Cover the bowl and chill the dough in the refrigerator for at least 30 minutes. This step is crucial for texture and shape.

Remove the chilled dough and roll rounded tablespoons of dough firmly between your palms to form smooth, uniform balls about 1 inch in diameter. Place them onto the prepared baking sheets.

Bake the cookies for 12 to 15 minutes, or until the bottoms are very lightly golden brown. The cookies should still appear pale white on top.

While the cookies are baking, prepare the coating: In a shallow dish, whisk together the 2 cups of powdered sugar and the 2 tablespoons of ground cinnamon.

First Roll (Warm): Immediately upon removing the cookies from the oven, allow them to cool on the baking sheet for 2 to 3 minutes. While still warm, gently roll each cookie in the cinnamon sugar mixture until fully coated. Set them on a wire rack to cool completely.

Second Roll (Cool): Once the cookies are completely cool (30-45 minutes), roll them a second time in the cinnamon sugar mixture. This ensures the maximum 'snowball' coating effect.

Serve immediately or store in an airtight container at room temperature for up to one week. Do not refrigerate the finished cookies, as this can cause the coating to absorb moisture.