Preheat the oven to 350 °F (175 °C) and line a baking sheet with a piece of parchment paper. Break up the almond paste into about 2" chunks and place in the bowl of a food processor fitted with an S-blade. Add the remaining dough ingredients and pulse until a dough forms. It'll be sticky but workable. Break up the almond paste into about 2" chunks.
Set on a baking sheet. Preheat the oven to 180°C / 350°F and bake the almond crescents for 10 to 15 minutes or a little longer if you want them more crisp. Let them cool and in the meantime, melt the chocolate in a bowl over hot water. Once the almond horns have cooled completely, dip the ends of the horns into the chocolate.
Preheat oven to 350 F. Mix all ingredients in a large mixing bowl, and let stand for 1 hour in the fridge. Roll small walnut-sized balls of dough into strips that can be shaped into a horn (or horseshoe) shape, and brush with egg white. Bake for 15-17 minutes. Storage: Let these sit in a sealed container overnight.