Real food is the answer.
To drive your appetite, you need to have an understanding of the role that insulin plays in anabolism, and blood sugar. It's the shuttle hormone, but... it also drives your blood sugar lower, and, as an effect, your appetite follows.
I.e., aside from eating real food (solid protein, complex carbs, poly and mono fats), you can throw some fast carbs in to "push" nutrition into your cells. Fast carbs cause your blood sugar to rise quickly, and insulin follows. That is, if you eat sweets, it'll literally make you hungrier. (Part of why fat asses, get and stay fat, and...are constantly hungry.) Now, too much sugars can be damaging to your heart, so, you have to sit on the fence between being anabolic, storing fat, and driving hunger. As much as anything, hunger levels are driven by blood sugar. There are other mental and biological things at work, but, it's mostly around blood sugar.
You can add some saturated fats (think pizza, beef, etc.) and you'll get more calorie dense food. We need some saturated fat, but, too much is hard on a lot of your body's systems.
If you eat cleanly, it's hard to get enough calories for gains. In my case, I'm when I was younger, I grew up eating meat and potatoes, but, very little fried food. I'm now in my 40'th year of lifting / cardio. When I was 17, I was 5'5" and 175. Now, I get as heavy as 230#. Genes are important as a factor, but, ... as much as anything gaining weight is about getting enough good calories.
You need to be eating good nutritious, solid, food, at least 4 times a day. The shakes are o.k. for adding calories.
I assure you, if you eat more calories than you consume, you WILL gain weight. You can't fear food.
You can "dirty bulk" on the "see food" diet. You may pickup some fat, but, you'll gain.
At 54, without really trying to hard, I carry 195 to 205. My genes are very good. 130 is o.k., but, I suspect you just plain aren't consuming enough calories.
I'm not talking about force feeding. I'm talking about stoking your hunger.
And, yes, peanut butter is a good source of poly and mono fats, along with some protein. Most nuts are really good for you.
At the end of the day, be grateful that you aren't overweight. Many fat folks would love to be in your spot. :-)