Preheat oven to 350 degrees. Prepare spring form pan for thecake. In a small bowl make streusel by adding flour, sugar and tub margarineand mixing it until it becomes crumbly.  In a large mixing bowl: addflours, sugar, baking powder, baking soda, flax meal, orange zest and saltwell. In a separate smaller bowl, add yogurt, orange juice and vanilla and stirwell. Add the wet ingredients into the dry ingredients and stir well. Addcranberries and walnuts. Stir well again. Add to spring form pan and add thestreusel. Bake cake for 50 minutes. Check the middle with a toothpick to makesure that it comes out clean. Allow it to cool and then open the spring so youcan carefully take the pan off the sides. Leave the bottom of the pan alone andplace it on a decorative plate. Garnish with a few fresh or thawed frozencranberries if desired. As you can see below, I also added a dollop of yogurtto my piece. Some of you may even want to add a little whipped cream!