Preheat oven to 400°F. In a large bowl, cream butter and sugar. Beat in egg and vanilla. Mix baking powder and flour, add one cup at a time, mixing and scraping sides of bowl after each addition. The dough will be stiff. Roll out dough on floured wax paper. Using a round cookie cutter cut out cookies. Be sure to cut out an even number of circles. Then take the smaller cutter and cut the centre out of every second cookie. Bake the cookies for about 6 minutes. Watch carefully! Once the cookies have cooled, match up tops and bottoms. Keep the browned side in for the bottom and top. Add 1 teaspoon or less of jam and spread over cookie. For the finishing touch, melt the chocolate chips in the microwave for 40 seconds. Stir and microwave for another 20 seconds or until smooth.