Cream together the butter and sugar. Add the almond extract, all-purpose flour, and cake flour, mixing until just combined.
Cover and place the dough in the refrigerator for at least one hour.
Remove the dough from the refrigerator and preheat the oven to 350F. Separate the dough into three or four pieces and roll each piece into a log of about ¾ inches in thickness.
Whisk the egg until the yolk and white are blended. Spread the egg wash over the logs. Sprinkle each log with chopped almonds and pearl sugar.
Cut the logs into pieces of about 2 inches in length. Bake for about 10 minutes or until the cookies appear slightly drier or slightly golden in color.