1In medium bowl, sift together flour and baking powder; set aside. In large bowl, beat together butter, sugar and egg until fluffy. Stir in vanilla extract. Gradually, add flour mixture, stirring until well combined. Roll out dough between two pieces of wax paper to 12x10' rectangle. Remove top piece of wax paper. Spread jam evenly over entire surface of dough. Sprinkle evenly with nuts. Firmly, roll up dough from a long side, jellyroll style , removing wax paper as you roll. Wrap roll in wax paper and refrigerate several hours or overnight.
2Heat oven to 375 degrees. Cut roll into generous 1/4" slices with thin sharp knife. Transfer slices to ungreased cookie sheet, spacing 2" apart. Bake 9 minutes. IMMEDIATELY remove from pan. Cool on rack.
3Hints for Success:
1. It's easy to have too much flour in this recipe. Spoon sifted flour into your measuring cup. If you scoop compacted flour out of the bag with a measuring cup, you will have a dry, hard-to-handle dough.
2. So that you don't squish raspberry jam out of the cookie roll, be sparse with the jam on the last inch of the dough.
3. Turn the dough log 1/4 turn after every few cuts to help keep the cookies round. If out of round, gently press the edges of the sliced dough to bring the cookie into shape.
4. Be sure to remove the cookies from the sheet while they are still warm. IF the jam cools on the sheet, they will be difficult to remove.