In a mixing bowl, add butter, vanilla and sugar. Beat on low speed until sugar is incorporated.
Slowly add flour on low speed and mix until blended. Add pecans and mix on low.
Roll dough into 1 ½ inch balls.
Place dough balls onto parchment paper lined cookie sheet.
Bake for 8-10 minutes.
Remove GENTLY with a thin spatula onto a cooling rack. These cookies are very crumbly when hot.
Allow to cool 15 minutes. Roll in powdered sugar.
I have tested this recipe with King Arthur Measure for Measure GF, Bob's Red Mill 1 to 1 GF blend, and Authentic Foods Multi Blend in this recipe. That doesn't mean others will not work, I just have not tested other flours.
If your gluten free flour blend doesn't contain Xanthan Gum, please add 1 teaspoon.
To make this recipe dairy-free, substitute the butter for vegan butter.
These cookies will keep up to 4 days in an air-tight container, or up to 4 months in the freezer.