Beat the softened butter, or the ghee or coconut oil alternative, with the powdered sweetener in a large bowl using a stand mixer, hand mixer, or fork; work in vanilla, almond flour, and salt, incorporate the pecans, then knead everything into one cohesive ball. Look for an aerated butter mixture before adding the flour and a dough that holds together afterward, adding almond milk only if it stays crumbly or a little extra almond flour if it feels wet.
Portion the dough into 1 tablespoon rounds, smooth them between your palms, arrange them about 2 inches apart on a parchment-lined baking sheet, and freeze the tray for 15 minutes while heating the oven to 375 °F. The shaped pieces should have smooth surfaces without open seams, and the chill should firm the fat before baking.
Bake for 12–14 minutes, turning the pan halfway through the baking time. Check for lightly golden bottoms beneath pale tops rather than waiting for the whole cookie to brown.
Leave the cookies undisturbed on the baking sheet for about 3–4 minutes after removing them from the oven. They should become comfortable to handle while remaining warm, though their texture will still be delicate.
Pass 1/2 cup powdered sweetener through a sieve into a medium bowl, gently roll the warm cookies in it, and transfer them to a cooling rack. Once completely cool and firmer to the touch, the cookies can receive another optional roll in powdered sweetener for a fuller white coating.
Pack the completely cooled cookies in an airtight container, or place them in an airtight freezer container for longer storage. The cookies should feel firm and have no residual warmth before packing so the coating stays as dry as possible.