If you want to be extra safe with your no bake cookie dough bars, you may want to heat treat your raw flour. This will eliminate potential microbes or bacteria that would otherwise be dealt with in the baking process. To heat treat, simply heat the flour to at least 160 degrees F. An easy way to do this is to spread your flour on a baking sheet and place in an oven at 350 degrees F for about 5 minutes, then use a food safe thermometer to check the temperature.