1. Line a large baking sheet with parchment paper. Preheat oven to 350 degrees F.
2. In a large bowl, combine butter, sugar, and eggs with a mixer for about 1 minute or until well blended. Mix in eggnog and rum or rum extract, just until blended.
3. In a separate bowl, combine flour, baking powder, nutmeg, and salt. Working in small batches, mix the flour mixture into butter mixture until all of the flour mixture has been added to the butter mixture and is well blended.
4. On a floured cutting board, divide dough in half. Shape each dough half into a long roll, approximately 14″ long. Carefully place rolls on prepared baking sheet, about 3″ apart from each other. With your hand, press down each roll so that they are approximately 1/2″ high.
5. Bake for 25 minutes or until golden brown. Carefully remove from pans and place on cooling racks. Set aside baking sheet, as it will be reused. When biscotti had cooled enough to handle, but is still warm, carefully move them to a cutting board and cut crosswise slices (approximately 1/2″ in size).
6. Place slices, cut side down, back on original baking sheet. Bake for 10 minutes. Turn slices over and return to oven to bake for another 10 minutes or until somewhat firm and lightly browned. Transfer to wire racks to completely cool, with tops upwards.
7. To drizzle with glaze: with biscotti pieces no more than 1″ apart from each other on either the wire rack or your baking sheet, tip tines of a fork into the glaze, allowing some of the excess to drip off. In a back and forth sweeping motion, about 6″ above biscotti, allow the glaze to fall in lines on top of the biscotti. Continue until glazed as desired or until all glaze has been used.

Glaze

1. In a small bowl, mix together powdered sugar, rum or rum extract and 2 tablespoons eggnog. If needed, add more eggnog to achieve desired consistency (I use 3 tablespoons total of eggnog).