Combine rolled oats and sugar.
Then stir in shortening and egg.
Sift together flour, baking powder, and salt, and add alternately with combined milk and vanilla to first mixture.
Drop by teaspoonfuls about 2" apart onto greased or oiled cookie sheets.
Flatten to 1/8" thickness with soatula wet in cold water.
Then bake in moderately hot oven of 400º F.for 10 min.
Remove wafers from cookie sheets as soon as them are removed from the oven.