1. In a large bowl, whisk together olive oil, vinegar, garlic powder, basil, oregano, black pepper, and sugar. Add cooked pasta, mushrooms, tomatoes, red peppers, feta cheese, green onions, olives, and pepperoni. Toss until evenly coated. Cover, and chill 2 hours or overnight.
My Note: I made it. I tried it after chilling it for a couple of hours and wasn't too thrilled with it. I just made a bowl now, after it being in the fridge overnight and wow! It isn't dry at all and the flavors have really mingled and developed! I followed family and friends suggestions and used half balsamic vinegar instead of all red wine vinegar. I also used rotini pasta, regular tomatoes, portobello mushrooms, red and green bell peppers, and a small purple onion. I left out the pepperoni just because I didn't have any, but next time I'll definately add it. As good as it tastes, if you do use balsamic, be warned that the pasta and feta will look brownish. I think someone else mentioned this, but if you're making for company, you might want to use white balsamic vinegar. However, the vinegar/oil ratio is a little strong for me. I recommend that you start with approximately 1/4 cup of vinegar (you can adjust and add more if you like) using half red wine vinegar and half balsamic as suggested by other reviews. I substitute 1 can artichoke hearts-not marinated-for the mushrooms. I also used diced red and yellow peppers for extra color and sliced olives. I prefer red onions instead of green onions and use tomato basil feta cheese and bowtie pasta.