1. Combine first 3 ingredients and, if desired, cardamom in a medium bowl; beat with a mixer at medium speed until creamy. Spoon cream cheese mixture into a small zip-top plastic bag, and seal bag. Carefully snip off 1/4 inch of 1 bottom corner of bag.
2. Pipe about 2 teaspoons cream cheese mixture down center of each date half. Serve at room temperature, or cover and chill until ready to serve.