What is a good brand of instant powdered espresso with the finest grind ?

I’ve never bought this before. I don’t want to make it to drink. I want to add it to ice cream to make it coffee flavored.

Therefore I need the one that is the most finely powdered.

I know that some instant coffee brands are crystals (like Folgers) but I obviously don’t want that.

I’m hoping to get a fine powder which will mix in easily without going to the expense of buying one brand after another.

Any recommendations ?