1. Pulse almonds in a food processor until very finely ground (do not over process, or nuts will turn into butter). Transfer to a bowl. Add cranberries with flour to processor and grind until cranberries are very finely chopped. Add to bowl with zest.
2. Preheat oven to 350 degree F and line 4 large cookie sheets with parchment.
3. Melt butter with sugar and cream over moderate heat, stirring, until smooth and slightly thickened. Bring mixture just to a boil over moderate heat, stirring. Remove pan from heat and stir in almond mixture until just combined. Immediately spoon scant tablespoons about 4 inches apart onto prepared sheets and with the back of a wet teaspoon, or finger, spread batter into 2-1/2-inch rounds.
4. Bake wafers in batches in middle of oven until a rich golden brown, about 8 minutes. Transfer pans to racks to cool (cookies will crisp once cool) until firm enough to be lifted, about 2 minutes. Carefully transfer wafers with a metal spatula to racks to cool.
5. Melt half of chocolate in a metal bowl set over a saucepan of simmering water, stirring until smooth. Remove bowl from pan and add remaining chocolate. Let stand for 3 minutes. Whisk chocolate until smooth.
6. Fill a small sturdy resealable plastic bag with melted chocolate. Push chocolate to one corner of bottom of bag and snip that corner to make a small opening through which to pipe chocolate. Pipe chocolate in a zigzag motion across top of each cookie and transfer to a parchment-lined tray. Chill cookies until chocolate is firm, about 5 minutes.
7. Wafers will keep for 1 week stored between sheets of waxed paper in an airtight container at room temperature. Makes about 3 dozen wafers.