Candied grapefruit peels add an extra flavor contrast as well as a pretty finish.
Add rye; beat until combined.
Whisk all-purpose flour, pastry flour, cardamom, baking powder and salt in a medium bowl.

Photo: William Dickey
Shape the dough into a log about 134 inches wide and 12 inches long.
Wrap in parchment paper and refrigerate until firm, about 1 hour.
(Reserve the grapefruit flesh for another use, such as fruit salad.
)Place the peels in a small saucepan and add 2 cups water.
Cover and bring to a boil over high heat.
Drain the water from the pan.
Repeat two more times.
Meanwhile, preheat oven to 350F.
Slice the cookie dough into 1/4-inch-thick rounds and place the rounds 2 inches apart on the prepared baking sheets.
Use a fork to press a crosshatch pattern into the tops of the cookies.
Bake until the edges are lightly golden brown, 12 to 15 minutes.
Transfer the cookies to a wire rack to cool completely, about 20 minutes.
Cut the candied peels into thin strips or dice.
Toss with the remaining 1/2 cup sugar.
Remove the peels from the sugar.
Place chocolate in a microwave-safe medium bowl.
Microwave on Medium for 1 minute.
Stir, then continue microwaving on Medium, stirring every 20 seconds, until melted.
Dip half of each cookie in the melted chocolate and return to the wire rack.
Top the chocolate-dipped part of each cookie with some of the candied grapefruit peel.
Let the chocolate set, about 1 hour.
To make ahead
Store candied grapefruit airtight at room temperature for up to 6 months.
Store the decorated cookies airtight between layers of parchment paper for up to 2 weeks.
- Daily Values (DVs) are the recommended amounts of nutrients to consume each day.
(-) Information is not currently available for this nutrient.