In a food processor, combine the flour, ginger and cloves. Add butter; cover and process until mixture resembles coarse crumbs. Add the brown sugar, molasses and egg; cover and process until blended. Wrap dough in plastic wrap; refrigerate for at least 30 minutes or until firm.
Unwrap dough; knead until smooth, about 8 times. On a lightly floured surface, roll out dough to 1/4-in. thickness. Cut out eight trees with a floured 5-in. tree-shaped cookie cutter. Cut out eight 3-in. round circles, rerolling dough scraps if necessary.
Place 2 in. apart on a greased baking sheet. Bake at 400° for 6 minutes. Using a plastic straw, cut out circles in a random pattern on the trees (so candlelight can shine through). Bake 6-7 minutes longer or until firm. Remove to wire racks to cool.
For icing, in a large bowl, combine the confectioners' sugar, meringue powder and cream of tartar. Add water; beat on low speed for 1 minute or until very stiff.
Cut a small hole in the corner of a pastry or plastic bag; insert a #5 round pastry tip. Outline trees and decorate trees with garland and ornaments as desired. Pipe icing onto the bottom edge of each tree; set tree on a round base about 1/2 in. from edge. For additional support, pipe another line of icing along the back of tree where it joins the base. Prop trees with small glasses until icing has set. Let stand overnight to dry completely. Store in an airtight container.
Place a votive candle or tea light on the base of holder behind the tree, or attach a birthday candle with a dab of icing on the base. Be aware that the heat will eventually soften the icing. Yield: 8 candle holders.