1. In large bowl, with mixer on high, beat butter and sugar until light and fluffy, about 3 minutes. Add melted chocolate and malt; beat to combine. Add eggs and vanilla, and beat 2 minutes more. Reduce mixer speed to low and add flour, baking powder, and salt. Beat until combined.
2. Refrigerate for 3 hours.
3. Heat oven to 350°F. Shape tablespoons of dough into balls. Drop balls into confectioners' sugar, coating well. Place balls 1" apart on ungreased baking sheets. Bake 12 to 15 minutes or until edges are slightly crisp. Let cool 1 minute on baking sheet. Transfer cookies to wire racks, and let cool completely.