Mix in vanilla, flour, baking powder and nuts. Bake at 325 degrees or until lightly browned. Roll in powdered sugar if desired. If dough becomes too dry, add small amount of orange juice or milk. Cookies should, however, mound when dropped from teaspoon.
Cookies keep well frozen.
I've never rolled mine in the powdered sugar - like them just the way they are. In a large bowl, cream the butter and the sugar until light, then add the egg and beat well. Sift the flour before measuring and blend with the salt. Beat into the butter mixture with the rind and vanilla. Add the oatmeal and chocolate bits.