Preheat your oven to 350 degrees F. and line 2 large baking sheets with parchment paper.
In the bowl of a stand mixer or a large bowl, combine the peanut butter, brown sugar, vanilla, cinnamon, and eggs. Mix with the stand mixer or a hand blender until smooth.
Add the oats, cranberries, pepitas, sunflower seeds, and walnuts to the bowl and mix until just combined.
Using a 2 Tbsp scoop, place the dough onto the parchment-lined baking sheets. Using your hand, press the dough into a cookie shape on the pan. You can also place the dough into your hand, whichever you find better to shape the cookie. Make sure you leave at least 1 inch of space between each cookie.
Bake in the preheated oven for 12 -15 minutes.
Allow the cookies to cool on the baking sheet for a few minutes; this will help them firm up.
Serve them warm or allow them to cool completely and store them in an air-tight container in the fridge for up to a week. These cookies also freeze well.