Cream butter and sugar together; add yolk of egg.
Then add 1 cup flour and a pinch of salt.
Mix pecans with a tablespoon of flour and add to above mixture.
Beat egg white until stiff.
Add that and vanilla last of all.
Take a teaspoon of the mixture, dip in ice water and spread with a spatula on greased cookie sheet.
Heat oven to 350℉ (180℃).
Turn off as soon as cookies are put in.
Leave in oven until lightly browned.