Preheat an oven to 350 degrees F (175 degrees C). Grease and flour a 10 inch tube pan or Bundt pan.
In a large bowl, beat together the eggs, water, whipped topping mix, yellow cake mix, and poppy seeds until light and fluffy, 3 to 4 minutes. Pour into the prepared pan.
Bake in the preheated oven until a toothpick inserted into the center comes out clean, about 40 minutes. Cool in the pan for 10 minutes before removing to cool completely on a wire rack. Sprinkle with the confectioner's sugar.