Thumbprints(An Old Family Recipe)  
["2 1/4 c. flour", "1 1/4 tsp. baking powder", "1 c. butter", "1/2 c. sugar", "2 egg yolks", "1 tsp. vanilla", "jelly or preserves"]
["Sift flour and baking powder.", "In medium bowl with mixer, cream butter, sugar, egg yolks and vanilla until fluffy. Gradually mix in flour and baking powder until well blended. Cover bowl with wax paper and refrigerate until easy to handle, about 1 hour."]
["flour", "baking powder", "butter", "sugar", "egg yolks", "vanilla", "preserves"]