Lightly spray a 8" x 8" x 2" baking dish with Pam and set aside.
FILLING: In a small bowl, beat cottage cheese, cream cheese, egg yolk, sugar and vanilla with electric mixer till nearly smooth (about 2 minutes). Set aside.
BATTER: In a medium bowl, beat sour cream, butter, orange juice, and eggs with electric mixer on low speed until smooth.
Add flour, 3 tablespoons of sugar and baking powder.
Beat for 2 more minutes until smooth.
TO ASSEMBLE: Spread 1/2 the batter in the greased baking dish.
Spoon cheese filling in small spoonfuls on top.
Carefully spread remaining batter on top.
Place in the oven for approximately 40-45 minutes until puffy and golden. (Watch closely for the last 5 minutes so not to overcook).
Serve immediately with Blueberry sauce or syrup.
BLUEBERRY SAUCE:
In a sauce pan over medium heat, stir together the sugar, cornstarch, cinnamon and nutmeg.
Slowly stir in water.
Cook and stir frenquently until thickened, then cook 2 more minutes.