Preheat oven to 355 degrees F .

1. Using an electric mixer, add eggs and margarine to mixer bowl and beat at high speed.
2. When the margarine has been well blended (about 2 minutes).
3. Add yogurt and reduce mixing speed to medium-low until it starts to blend in, then increase to high.
4. Let the mixture continue to beat and brush the bottom and sides of the baking pan with olive oil.
5. Mix or sift together the flour and baking powder and add to mixing bowl.
6. Add crumbled feta 1/4 of the quantity at a time to allow to mix in.
7. Scrape sides of mixing bowl occasionally to push cheese in toward center.
8. Continue mixing at high speed for 6-8 minutes until very well blended and creamy (small pieces of cheese will still be visible).
9. Pour into baking pan and spread evenly.
10. Bake at 355 degrees F for 40 minutes (check at 35 for doneness) until golden brown.
11. Use a sharp knife to cut into small squares, diamonds, or triangles.