preheat oven to 350°, line large cookie sheet with parchment and set aside
in a bowl combine butter, sugar and eggs until well blended
mix in eggnog and brandy, just until blended
in a seperate bowl combine flour, baking powder, salt, nutmeg
working in small batches add flour mixture into egg mixture until dough comes together
turn dough out onto a floured workspace bring together completely, divide in half, shape each half into a log 14"-18" long
place on baking tray, 3" apart, press logs down until they are about ½" high
bake for 25 min until golden brown
remove from oven, let cool for 10 minutes
slice at an angle, return cookies to baking tray cut side down
bake for an additional 7 minutes, remove from oven, turn over and toast the other side for 7 more minutes
remove from oven, cool completely
combine powdered sugar, eggnog and brandy in a bowl, glaze cool biscotti and let set