Jacque Pedersen has a tutorial on her blog for window cards. NZSU have a challenge to make a card using window technique.
They are both Birthday Cards.
First one is made using Pacific Point and Basic Black card stock and the hedgehog out off the Fun and Fast Notes stamp set.
The second one is made using Kiwi Kiss and Creamy Caramel card stock and the cakes out off the same stamp set.