1/2 cup reduced-calorie margarine |
1/4 cup unsweetened cocoa |
3/4 cup sugar |
3/4 cup all-purpose flour |
1 teaspoon baking powder |
1 1/2 teaspoons vanilla extract |
2 egg whites |
vegetable cooking spray |
1 (1-ounce) package pre-melted unsweetened chocolate |
1 quart cookies-and-cream nonfat frozen yogurt |
4 low-fat cream-filled chocolate sandwich cookies, cut in half (optional) |