Line two baking sheets with parchment paper or silicone baking mats.
Add butter, sugar, milk and cocoa powder to a medium saucepan. Bring to a rolling boil. Let it boil for exactly 1 minute. (I recommend setting a timer.)
Remove saucepan from heat and add in Nutella and oats. Stir until everything is evenly and well combined.
Scoop up a heaping 1.5 tbsp of batter and place onto prepared baking sheet. Repeat with remaining cookie dough.
Using the back of a spoon, flatten cookie dough balls into rounds that are about 1/4 inch thick and look like a finished cookie. Let cookies set for 1 hour.
Notes
Nutella spread can be replaced with peanut butter, almond butter or other similar nut butter spreads. If you do use a different nut butter, you may need to increase the sugar. Since Nutella is already very sweet, I used less sugar in the recipe.
I measured out a little more than 1.5 tbsp of cookie dough for each dough ball so that the final outcome is regular cookie size. You can make smaller cookies as well.
You can use any milk, I used low fat.
Make sure to boil the mixture for exactly 1 minute. Use a timer so you don't go over.
The nutrition information provided are only estimates based on an online nutritional calculator. This is not a comprehensive list of all the nutrients in the recipe (i.e., does not include vitamins, cholesterol, etc). I am not a certified nutritionist. Please consult a nutritionist or doctor for accurate information and any dietary restrictions and concerns you may have.