Cream butter and cheese. Sift flour and baking powder and add to creamed mixture. Chill dough 2 to 3 hours. Heat oven to 375 degrees, quick moderate.
Mix nuts, jam and granulated sugar. Divide dough into 4 equal parts; work with 1/4 of dough at a time. Refrigerate remaining dough. Roll dough very thin (1/16 inch) on lightly floured cloth-covered board. Cut 2 inches squares. Place on baking sheet. Place 1 teaspoon nut mixture in center of square and top with another square of dough.
Press edges together with floured tines of a fork. Bake 15 to 20 minutes, or until lightly browned. When completely cooled, sprinkle tops with confectioners' sugar. Makes about 5 dozen.