Preheat oven to 375 degrees F. In a large bowl, beat butter with an electric mixer on medium to high speed for 30 seconds. Add sugar, baking powder, 1/4 teaspoon nutmeg, and salt. Beat until combined, scraping bowl occasionally. Beat in egg and rum extract until combined. Beat in as much of the flour as you can with the mixer. Using a wooden spoon, stir in any remaining flour.Advertisement
Place dough in a pastry bag fitted with a 1/4-inch open star tip. Pipe dough in 3- to 4-inch-long letters or other shapes about 1 inch apart onto an ungreased cookie sheet.
Bake in the preheated oven for 7 to 9 minutes or until edges are firm but not brown. Transfer cookies to a wire rack; let cool.
In a small saucepan, combine white chocolate and shortening. Cook and stir over low heat until melted and smooth. Drizzle chocolate mixture over cooled cookies. If desired, sprinkle with additional nutmeg. Let stand until chocolate is set. Makes about 24 cookies.
Layer cookies between sheets of waxed paper in an airtight container; cover. Store at room temperature for up to 3 days or freeze for up to 3 months.