Preheat the oven to 425 degrees F (220 degrees C).
In a large bowl, mix together the cottage cheese, eggs and feta cheese until well blended. Brush melted butter onto one sheet of phyllo dough at a time, and layer them in the bottom of a 9x13 inch baking dish until you have 7 sheets. Let the sheets rest up against the sides of the dish as well. Spread the cheese mixture over the phyllo layers, then repeat the process with 7 more sheets, tucking in the sides around the edges.
Bake for about 30 minutes in the preheated oven, until golden brown and crisp. Cut into squares and serve warm.
This recipe can also be prepared by spooning the filling onto cut buttered phyllo strips and folding into repeated triangles.