Cream the butter: Get out a stand mixer (or a large bowl and a hand mixer), and add both the 2 cups of butter, and both types of sugar. Mix all of this up for about two minutes, and then add in the eggs, and vanilla extract. Keep mixing all of this together for another 3 minutes or until all of the ingredients are smooth and shows no visible chunks. These are our wet ingredients, set them aside to be used later in the recipe.

Blend the oatmeal and Hershey bar: Get out either a blender or a food processor, and begin by blending up the Hershey's chocolate bar until it forms small crumbs. Set that aside to be used in the following step. Next blend up the oatmeal in batches so that it forms a chunky powder. Again set that aside to be used in the following step.

Make the cookie dough: Slowly add the dry ingredients to the wet ingredients in batches, making sure that they are properly mixed together. If you are using a stand mixer then simply turn the mixer on low, and add about a cup of the dry ingredients every 20 seconds, until you have incorporated all of the dry and wet ingredients together. After you have incorporated the wet and dry ingredients together, the last step is to add both the chocolate chips, and walnuts. Simply toss both ingredients into your bowl and lightly mix them in so that they are well dispersed throughout the cookie dough.

Let sit: Separate the dough into large brick sized pieces, and wrap each piece in aluminum foil. Then place these either into your refrigerator for a day, or into your freezer if you plan on baking these cookies at a later date. However if you do place the cookie dough in the freezer, make sure to place it into your fridge for a day in order for the dough to defrost before using.

Bake: Take the cookie dough out of your refrigerator, and preheat your oven to 375 degrees Fahrenheit. Next get out a large cookie sheet, and start separating the cookie dough into balls about half the size of a golf ball. One easy way to do this is to use a melon baller, however if you have thought of another easy way to do this, then by all means do it that way. Next place these balls of cookie dough out on your cookie sheet, making sure that they are placed at least 2 inches apart from each other. Then either take the palm of your hand, or a spatula, and slightly flatten out the balls of cookie dough, but make sure to not flatten them out completely. Once you have filled up a cookie sheet in this manner, then stick it in your oven, and let it bake for 6 to 8 minutes. After the cookies have been baked let them sit out on your kitchen counter for about 2 minutes before removing them from the cookie sheet.