Put spinach in a large microwave-safe bowl and drape bowl with microwave-safe plastic wrap. Microwave until spinach is tender, stirring a couple of times, 4 to 5 minutes. Drain spinach and let stand until cool enough to handle. Squeeze out liquid, then finely chop.
Whirl cottage cheese, parmesan, salt, and pepper in a food processor until very smooth, about 1 minute, scraping inside of bowl as needed. Scrape into a bowl and stir in spinach. Serve dip at room temperature or chilled, with baguette toasts or crackers.
Make ahead: Up to 2 days, chilled.
Note: Nutritional analysis is per 3-Tbsp. serving.