Heat oven to 350°F.

Spray 9-inch square metal baking pan with cooking spray or grease lightly.

For streusel, combine all ingredients in small bowl; mix well.

Set aside.

For coffeecake, beat sugar and margarine with electric mixer in large bowl until fluffy.

Add egg whites, sour cream and vanilla; mix until smooth.

Add combined flour, oats, baking powder and baking soda; mix just until blended.

Spread into pan.

Spoon preserves over batter; swirl through batter with knife.

Sprinkle blueberries evenly over batter.

Sprinkle streusel over blueberries.

Bake 50 to 55 minutes or until wooden pick inserted in center comes out clean.

Serve warm.

Store tightly covered at room temperature.