Feel free to play around with the ingredients to suit your taste -- or region. Most of the Southwest ingredients are best found online, but you should be able to find amaranth in a lot of supermarkets and pretty much every health food store.
Grease a sheet pan with butter, oil or cooking spray. Ideally you'd use an 8x8 pan, but anything close to that will work.
Pop the amaranth. The link above goes to a video on how to do it, but it's easy: Get a pot hot over medium-high heat and put about a tablespoon of amaranth seeds in at once. They will pop almost immediately. Move them to a bowl and repeat until you have your 1 1/4 cups. Don't put too much amaranth in the pot at once or it will not pop correctly. It goes really fast, so no big deal.
Mix the chopped dates with the oats, popped amaranth, nuts, mesquite flour, cinnamon and salt together in a bowl.
Put the pine nut butter (or whatever nut butter you use) into a small pot with the syrup or honey and stir together over medium-low heat until well combined. Let this cool for a couple minutes, then stir in the vanilla extract.
Add the nut butter-syrup mixture to the dry ingredients in the bowl, and mix a little. Add the chocolate chips and mix everything well. Move everything to the greased pan and spread it over the bottom of the pan evenly. Pack it good, then let it sit out for an hour or so to set fully. Use a sharp knife to cut out bars, squares or whatever shape you like and wrap with some wax paper. Eat when hungry.
Once made, these bars kept for two months in the fridge, and a full month in a closed container at room temperature in my truck, so they are pretty hardy. They do get more crumbly as they age, however.