Preheat the oven to 180°C (350°F) and grease a 9×13-inch baking dish (or a similar-sized dish) with butter.
In a large mixing bowl, whisk together the cottage cheese, eggs, milk, honey, vanilla extract, pumpkin purée, cinnamon, nutmeg, and salt until well combined and mostly smooth.
Stir in the rolled oats and whole wheat flour until evenly combined.
Pour the batter into the prepared baking dish and spread it into an even layer. Sprinkle the chopped walnuts or pecans evenly over the top.
Bake for 35–40 minutes, or until the edges are lightly golden and the center is set. A knife inserted into the center should come out mostly clean.
Let the bake rest for 5–10 minutes before slicing. Drizzle with honey or maple syrup, if desired, then cut into squares or slices. Serve warm with a dollop of whipped cream or homemade yogurt.