Sift flour with baking soda and baking powder. In small mixing bowl cream butter and ONE cup sugar until light and fluffy. Beat in egg. Add ONE tsp nutmeg and the cardamom. Fold in flour, alternating with buttermilk.
Pour in greased 9" square baking pan (batter will be thick).
Combine remaining sugar and nutmeg (I like to add another 1/8 tsp of cardamom to the sugar); sprinkle evenly over batter.
Bake at 350 F for 30-35 minutes, until toothpick inserted in center comes out clean. Cool on wire rack.