Yes, you can cook with protein powder, but the effects of heat can vary depending on the type of protein powder and how it is being used.
For example, whey protein powder can be more heat-sensitive and may denature when exposed to high heat. This can cause the protein to lose some of its nutritional value and affect its taste and texture. That said, it should still maintain over 80% of its nutritional value even after being heated to over 160 degrees.
However, some plant-based protein powders, such as soy protein powder, are more heat-stable and can be used in cooking without significant loss of nutritional value.
When using protein powder in cooking, it's best to follow the specific instructions for that product and to consider the effects of heat on its nutritional value and taste. Additionally, it's important to note that cooking with protein powder can result in a different texture and taste compared to using it in its raw form.