Gaining

My body is built on Häagen-Dazs. I agree about the speed thing with a microwave, but I haven't had one for years, so have grown used to letting it melt naturally and I prefer it cool/room temp. I kid myself it is just a milkshake or something. But if you're going down the melted ice cream route I'd just double down, add some cream, blend in some oats and a cheesecake and make a weight gain shake. Yummy

Recently, I noticed Haagen Dasz has gone on sale near me, which it hadn’t ever done before. My wife has take a shine to the creamy mango variety while I tend to go for the chocolate chip cookie dough flavor. We don’t own a scale, so I’m always estimating our weights, but we’ve probably gained 10 pounds easily since the sale started ;-)

What Will I extra gain if u try 500 ml a day for 3 weeks?

I didn't do exclusively ice cream, I mixed it with heavy cream, and cake mix (and was funneling it as well). I feel like the scale didn't climb much because I was hiding that I was doing that so I was bad at doing it consistently, but that was probably when I grew stretch marks the fastest. The heavy cream really helped to tame the sweetness.