Preheat oven to 350 degrees F. Grease and flour an 8 inch cake pan (you can use butter, shortening or flour-added cooking spray).

Sift or thoroughly mix together the flour, baking powder and salt. Set aside. Again, make sure the dry ingredients are very uniformly mixed.

Place pistachios, cardamom and ½ cup of sugar in food processor and process until pistachios are fine. Add the flour mixture and pulse 3 or 4 times or until blended. Add the chunks of butter and pulse until mixture is crumbly.

In a separate bowl, stir together eggs and sour cream (or yogurt) until well mixed. Add egg mixture to food processor and process just until blended. Don't overprocess, but make sure ingredients are uniformly moist

Dump batter into prepared cake pan, scraping remainder from processor. Bake for 35-45 minutes or until a skewer inserted comes out clean. Let cool in pan on a rack for 10 minutes, then invert and allow cake to finish cooling. Keep pan handy.

Zest the lime to make about 1 tablespoon of zest (green part). Juice the lime and collect as much juice as possible. Add water to lime juice to make ⅓ cup plus 1 tablespoon liquid. Place water/lime juice mixture in a saucepan and add the ¼ cup sugar. Turn heat to medium and bring to a boil. Add lime zest. Reduce heat and simmer for 5 minutes. Strain lime zest. Let cool for about 10 minutes. Liquid should be slightly thick.

Now glaze the cake. Use the skewer to poke neat holes in the top of the cake. Pour liquid over top and let it sink down. Let it sit for a while then serve. If you want to cover the holes, sift confectioner's sugar over the top.