Make Classic Shortbread dough with just 1 cup flour. Add 1 cup ground oats and 3/4 cup finely ground hazelnuts with the flour. Mix one-third of the dough with 1/4 cup chopped hazelnuts; freeze tablespoonfuls in clumps for 30 minutes. Press the remaining dough into a buttered 8-inch square pan. Spread with raspberry preserves and top with the frozen clumps. Bake about 50 minutes at 350 degrees.