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.