Instructions

1. In the bowl of your stand mixer or a large bowl, place butter and beat on medium speed for 1 minute.  Add in sugar, brown sugar, cinnamon, cardamom and salt.  Mix until combined.  Add in yogurt and egg and mix until combined. Slowly add flour and mix until just combined.  Fold in pistachios.  Cover and chill dough for at least 2 hours.  *Have dough come to room temperature for 20 minutes prior to baking.
2. Preheat oven to 375 degrees.  Line a sheet pan with a Silpat or parchment paper
3. On a lightly floured surface, divide dough in half.  Working with half a batch at a time, roll out into 1/8" thick.  Using a heart cookie cutter, cut as many hearts.  Re-roll scraps of dough and continue cutting hearts.  Repeat with second ball of dough until all dough has been used.  Using a small heart cookie cutter, cut hearts out of the center of half the heart cookies.
4. Place cookies onto prepared sheet pan and bake 6-8 minutes or until golden brown.  
5. Allow to cool on pan for 5 minutes and move to a wire rack to cool completely.
6. When cookies have cooled, stir red food coloring into frosting.  
7. Smear 1 teaspoon frosting onto bottoms of heart cookie without a cut out and top with cookies with a cutout center, to create a sandwich.