Place the garlic cloves (still in their skins) on a baking sheet and bake for 10 minutes, until they're soft and fragrant. Separately, mash the pumpkin and cottage cheese. In a large bowl, combine the mashed pumpkin, cottage cheese, drained and chopped sun-dried tomatoes, and the roasted garlic (squeezed from its skin). Mix well, then season with some salt and plenty of freshly ground pepper.
Divide the rested dough into 4 portions and roll each out as thinly as you can get it. If you have a pasta machine, aim for a 3mm thickness. Lay the rolled pasta on a dish towel and let it dry out a bit. Using a 3-inch crinkle-edged round cutter, stamp out about 30 rounds of pasta. Don't be afraid to gather and re-roll any scraps to use up almost all the dough.
Top 15 rounds with a spoonful of the filling. Lightly brush the edges of each filled round with water, then place another pasta round on top. Press firmly around the edges to seal them, ensuring no filling can escape.
Bring a large pan of salted water to a boil. Carefully add the ravioli and cook for 3 to 4 minutes. You'll know they're done when the pasta rises to the surface of the water.