The only place around which serves both coffee / desserts and also meals. We stopped by because we were a large group and some of us only wanted something to drink, while others also wanted to eat something, and the other places told us it wasn't possible.

They have a heated outdoor seating area and very good food and drinks, for decent prices. The portions are quite filling and the staff was extremely nice.
Sursa: Google

Great little place for some lunch soup on a cool, autumn day after visiting the castles. Veggie pumpkin soup for the vegetarian and goulash for something hearty. Kartoffelsalat was the perfect accompaniment. Quick service from a polite, English speaking waiter. Glad we stopped in.
Sursa: Google

Excellent food and serving. We enjoyed both lunch and dinner here and were really happy with the service. Food came quickly and the prices are more than fair. The location itself is amazing on a summer day, it offers quiet, greenery and great historic buoldings.
Sursa: Google

Carol Gastro Bierhaus is a German style restaurant in Sinaia near Peles Castle. There is a terrace outside and two floors inside the restaurant. The decor for the lower floor would remind you of a typical German pub restaurant. The upper floor has a more modern decor. My fiance and I arrived for a late afternoon lunch and the place was starting to get busy. The service was prompt and on point. My fiance ordered the gulash soup and I ordered the beef soup and a bratwurst/pretzel combo. The food came out hot and tasted delicious. We also had the apple strudel and papanasi for dessert which was great. Overall, it was a nice restaurant within the view of the castle.
Sursa: Google

Good place for tasty food. Nice service. Big portions, as usual in Romania.
In the photo: pork rolls in bacon and schnitzel.
Sursa: Google