I don't think so! I'd bake some soaked, raw walnuts on a low-ish temperature, like 200 degrees, if you really wanted to be paranoid
Walnuts (well, most nuts in general), are extremely high in polyunsaturated fats which oxidize very quickly and turn rancid when exposed to high levels of heat for an extended period of time and this is in general, not a good thing since rancid fats place quite a bit of oxidative stress on your body.
Doing it once in a while may not cause much harm, but if you're doing it regularly, I would cut the habit out. If I eat nuts, I'm eating them raw for just this very reason. Just my two cents though, and take it with a grain of salt.
Oh, who cares. For an occasional treat, it sounds delicious.
F 28/5'4/100 lbs
"I'm not a psychopath, I'm a high-functioning sociopath; do your research."
"I think the basic anti-aging diet is also the best diet for prevention and treatment of diabetes, scleroderma, and the various "connective tissue diseases." This would emphasize high protein, low unsaturated fats, low iron, and high antioxidant consumption, with a moderate or low starch consumption.
In practice, this means that a major part of the diet should be milk, cheese, eggs, shellfish, fruits and coconut oil, with vitamin E and salt as the safest supplements."
- Ray Peat