Prepare fresh pomegranate arils, if necessary.* Mix together in a bowl the yogurt, buttermilk, lemon juice and agave nectar until incorporated. Pass the mixture through a fine mesh strainer. Slowly add in the pomegranate juice last. Refrigerate the mixture for 1 hour until chilled. Spin through an ice cream machine, gently folding in arils for texture before freezing.
Preheat oven to 325°F. Separate the eggs, putting the whites in a large mixing bowl and the yolks in another large mixing bowl. Beat the egg yolks until light and foamy; slowly add the cold water and almond extract. Gradually beat in sugar and continue to whip until the batter is extremely thick and light in color. Sift the first three dry ingredients into the yolk mixture, folding gently. Meanwhile, beat the egg whites gently until foamy. Add cream of tartar and increase mixer speed, beating until soft peaks form. Pour the egg yolk mixture in a thin stream over the entire surface of the egg white mixture. Add the lemon zest and poppy seeds while gently folding the batter with a rubber spatula, making sure everything is completely incorporated. Coat a mini Bundt cake mold with butter and flour. Using a spoon, fill the mold with cake batter until each cup is just about three quarters full. Bake for 15 to 30 minutes, or until the cake springs back at your touch. Allow the pan to cool slightly, and then remove cakes to a wire rack to cool fully.
Reduce 2 cups of pomegranate juice over low heat with 1/2 cup of sugar until it has reduced in volume by half. Remove from heat and let cool for 1 hour.
This recipe also makes one 10-inch cake in a springform pan. Baking time: 1 hour.
*To prepare fresh arils, score 1–2 large POM Wonderful Pomegranates and place in a bowl of water. Break open the pomegranates under water to free the arils (seed sacs). The arils will sink to the bottom of the bowl and the membrane will float to the top. Sieve and put the arils in a separate bowl. Reserve 1 cup of the arils from fruit and set aside. (Refrigerate or freeze remaining arils for another use.)