Cut butter into flour with a pastry cutter until evenly mixed.
Add remaining ingredients and mix lightly with fork until the flour is moistened.
Gather dough together and press into a ball. Divide into 24 uniform pieces and roll each into a ball. Place in freezer until firm but not frozen.
While in the freezer make the filling. Beat egg whites until stiff. Gradually add sugar. Fold in ground pecans.
Pull out 6 balls out at a time of the freezer. Roll each piece on a flour surface into a circle about a 4-5" in diameter. * Pro tip - thinner the better.
Add 2 Tbs of filling onto each cookie. Spread on center 1/3 and fold sides 1/3 towards the center. Place folded side down on the baking sheet. Repeat until all the cookies are done.
Bake at 350 degrees for 15 minutes or until golden brown. Cool and sprinkle with powdered sugar.
