Does cooking ruin the protein?
The quick answer is no!
Let’s look deeper into this myth that still persists. You will hear "If you cook protein powder, the protein becomes denatured. If the protein denatures, your body won't be able to use it!"
Only one of those things are true. Yes, heating up protein (cooking or adding to coffee as example) does change or “denature” the protein, which is a chemical reaction that breaks down the cellular structure and changes the chemical bond “shape” of the protein molecule, which is naturally curled up in a spiral shape or three dimensional (1), when you apply heat (2) it the protein unwinds from that shape (3).
While this does change the shape, this doesn't damage the nutritional value of the protein. Our bodies absorb the exact same amino acids from the protein whether we cook it or not.
When we eat protein, we break it down into smaller parts called amino acids. For the growth of muscle and proper metabolism 20 amino acids are needed. 11 of them are non-essential. This means that our body can make them. The remaining 9 are called essential which means we need to acquire them through dietary intake.
If we don’t acquire these amino acids through diet, muscle tissue cannot grow or regenerate. Protein is also an essential macronutrient that not only helps build muscle and bones, but it is also needed to repair tissue, make enzymes and hormones. Protein acts as a messenger to coordinate the biological process between different cells 
If denatures protein was damaged and not usable, we would be drinking raw eggs vs. cooking and eating them. As that is the easiest way to visualize a protein being denatured. The egg white goes from a clear liquid state to a solid right in front of your eyes. But all that protein and those nutrients are still there for your body to utilize for muscle protein synthesis.
In plain language, cooking and heating the protein changes nothing when it comes to the nutritional value.
That includes the amino acid availability and protein quantity.
So give yourself permission to cook with your leanfit protein powder, and make some amazing pancakes, cookies, or another delicious creative recipe you enjoy with the protein.