1In a large bowl combine the flour, white sugar, ground cinnamon, baking powder and salt. Cut in the butter until the mixture resembles coarse crumbs. In a small bowl beat the egg and 1/4 cup of milk. Add this to the crumb mixture until the dough is moistened. Cover and refrigerate for at least 1 hour.
2Preheat oven to 375 degrees F (190 degrees C).
3On a lightly floured surface roll out the dough to 1/8 inch thick. Cut with a 2 inch round cookie cutter. Place on ungreased baking sheets.
4Bake at 375 degrees F (190 degrees C) for 8 to 10 minutes or until edges are lightly browned. Cool on wire racks. Once cool spread jam on half of the cookies then top each with another cookie.
5To Make Glaze: Combine the confectioners' sugar, 2 tablespoons milk and vanilla until smooth. Spread glaze over the cookie and decorate with red cinnamon candy before the glaze is set. Let dry. Using a small new paintbrush and green food coloring, paint holly leaves on cookies.