It is very high in fats so it is calorically dense, but they are the good fats shown to lower LDL cholesterol and high fats are shown to increase satiety. The idea behind it is to help make you feel fuller for longer so that way you are less likely to eat higher calorie foods which will make it easier to stay in a calorie deficit. You can definitely remove things or add less of some things to reduce the number of calories but I think it will be helpful to understand why each ingredient it used.

Oikos Pro Vanilla Yogurt - 100g - 71.8¢/serving -  93 kcal - 13.3g Protein, 2.0g Fat, 5.3g Carbs - Great source of protein to improve satiety and prebiotics for gut health, this is also going to provide the sweetness to our meal without the use of high calorie sweeteners

Bob's Red Mill Quick Cooking Rolled Oats - 1/2 Cup - 20.54¢/serving - 170 kcal - 5.0g Protein, 3.0g Fat, 31.0g Carbs - Great source of Fiber, Manganese and Iron

Chia Seeds - 2 Tbs - 30¢/serving - 100 kcal - 3.3g Protein, 6.0g Fat, 8.7g Carbs - 193% of daily Omega-3, contains all 9 Essential Amino Acids and can be used to make Yogurt a complete protein

Sliced Almonds - 10g - 8.8¢/serving - 58 kcal - 2.1g Protein, 5.0g Fat, 2.2g Carbs - 17% of daily Vitamin E, lower in fats and higher is protein and typically lower calorie than most nuts, almonds are the best all round nut out there

Chopped Walnuts - 10g - 7¢/serving - 64 kcal - 1.4g Protein, 6.4g Fat, 1.4g Carbs - 99% of daily Omega-3, great source B Vitamins such as B6 and B1.

2% Great Value Milk (couldn't find Costco milk online) - 1 cup (or as much will fit in the jar) - 16.8¢/serving - 122 kcal - 8g Protein, 4.8g Fat, 11.7g Carbs - We can swap around what type of milk we use depending on our goal, I will use 2% most of the time but if I am trying to lower calories, Skim is a great way to go.

I put the ingredients in a 16oz jar in the order listed above except for the milk, that will go in last, from here we can play around with the ingredients to prevent burnout and have fun.
The base of our recipe is  $1.548/serving - 607 kcal - 33.1g Protein, 27.2g Fat, 60.3g Carbs

So far, my favorite flavor combo is:

PB Fit - 2 Tbs - 32.7¢/serving - 60 kcal - 8g Protein, 2g Fat, 6g Carbs
Banana - half a banana - idk - 61 kcal - .7g Protein, .2g Fat, 15.5g Carbs

then throw on the lid and shake it all up.

we can swap out the fruit pretty easy for some fun flavor combos. usually, I find that we must stick between 50-100g of fruit to fit in the jar.

Some other flavor combos I have enjoyed:

Canned Pumpkin - 80 to 100g - 61.72¢/serving - 27 to 34 kcal  - 1.1g Protein, 0.3g Fat, 8.1g Carbs - great source of vitamins, A, C and E, and a powerful antioxidant
Ceylon Cinnamon - seasoned to taste - Ceylon cinnamon specifically because it is easier on the liver than what you will find the grocery store.
Pumpkin Pie spice - seasoned to taste

or

Strawberries - 80 to 100g - 22 to 32 kcal - .7g Protein, .3g Fat, 7.7g Carbs
Carnations Breakfast Essentials - 1 pack - 133 kcal - 5.1g Protein, 1.1g Fat, 27g Carbs - probably better things than this but it was what I had around, great flavor but added sugars and highly processed

or

Canned Peached - 80 to 100g - 35 to 44 kcal - .6g Protein, 0g Fat, 11.6g Carbs - one of the least nutrient dense fruits out there but very tasty.
Ceylon Cinnamon

or

Banana
Ceylon Cinnamon

I would probably suggest adding 1-4g of brown sugar, syrup or honey for the first little while so you can get used to the flavor and slowly reduce the amount of sweeteners