Fruit is not easy calories.

Please explain

They fill you up and are not a lot of calories.
You want something that you are calorie dense and can continuously snack on

apple
hard boiled egg
tuna
string cheese
dark chocolate pretzel
nuts

As someone who doesn't like nuts at all, it's difficult

go for juice. ~120 cals / 8 oz adds up pretty quick if you drink a few glasses a day

I find some fatty frozen yoghurt essential during my bulk phase.

500gr containing 680kcal. I mostly add some oat flakes to it cause too much dairy, you know.
The one I have also contain 27,5gr protein so perfect to get my protein in as well.

All for 1,24 Euro

Ice cream. Choc milk. Ramen noodles. Eggs with lots of cheese. Peanut butter. Sticks of butter

avocado
nuts/spoonful of nut butter (ze bestest being rainforest nut butter, which is cashew, brasil nut, coconut)
boiled eggs (we almost always have some in the fridge)

those are my go-to's for filling up fast & ez

Cliff bars are so fake its gross. Just bake your own bars.