Most people whose goal is to build size don't train often enough, but I'm a believer in high frequency training. Try this for one week: train every day.
Here's my suggested training split:
A key here is to make sure each workout doesn't exceed 45-50 minutes. This is achieved via supersets, giant sets, and short rest breaks.
You might need to find a new gym for this week because you won't have time to chit-chat. Also, you'll be too busy breathing hard to make small talk! Your heart rate will be way up and the sweat will be pouring.
You can expect to lift less weight than normal due to the cumulative fatigue of the short rest periods. That's fine. Instead of focusing on moving big weights, chase the pump.
On the seventh day, the full-body HIIT session should include upper and lower body and take no longer than 20 minutes. Skip rope, do burpees, sprint, swing kettlebells, use battle ropes... basically anything to get your heart rate up. Focus on variety; don't just do 20 minutes of a single exercise.
Drink Plazma™ during each training session to fuel the workout itself and greatly accelerate recovery. I wouldn't suggest doing 7 straight days of intense training without Plazma™.