I used to work at a fast food restaurant that makes blended ice creams (yes... probably the one you're thinking of). They had a list printed on the wall of specific amounts to put into each blend. If you followed it, the blend was a perfect mix of ice cream, treat, and air. If you didn't? You got a big splat on the counter.
And yet... day after day... workers would put in more nuts, more strawberries, more chocolate, more more more! Then they'd act very proud of their creation, while the customer got a mess to scoop up.
I recently went to a (much inferior) fast food place that made copies of the blended ice cream. They poured in so many m&ms that we couldn't eat the ice cream! So not what you're hoping for in 100+ weather.
Less is more, my friends, less is more.
(And PS? If you're supposed to keep the brownies in the fridge? Don't get lazy. Room temperature ones disintegrate in the ice cream. Thank you.)