1. Preheat oven to 325 degrees F. Line an 11" X 13" baking sheet with parchment paper (HIGHLY recommended!!) or spray/ oil the pan pretty well.
2. With a blender or food processor, turn graham crackers & sunflower seeds to crumbs/ sunflower meal. You can do them together, if you want. Mix all dry ingredients in one bowl; mix wet ingredients in another bowl; combine. Stir until there are no dry spots... this may take a minute. (Resist the urge to add more liquid; it just takes a bit of stirring! The mix should be just moistened, & pretty sticky.) Taste to see if more sugar is needed; it depends on how sweet your non-dairy milk or juice is... so sometimes I add that last 1/4 cup of brown sugar & sometimes not.
3. Pour the mix into the pan and spread it evenly. Oil your hands lightly; using the heels of your hands, go around the whole area of the batter pressing it down firmly, until you have a solid, firm, rectangle of batter (vs. clumps/ loose bits). Bake for 30 minutes; when done, edges are lightly browned.
4. OK, this next part is important: as SOON as it's done, you've gotta slice it or crumble it... I slice it into squares, with the pizza-slicer-- go slowly: at this point it's still pretty soft. If you want more of a snack-mix, you can crumble it up by using a spatula or spoon to stir it up, right after it comes out of the oven; it's good this way in GORP, or anywhere you'd use granola. Also, if you're not using parchment paper, go ahead & remove it from the pan (whether sliced or crumbled)... this gets very crunchy as it cools, & if you leave it in an unlined pan during that time, it is HARD to get out!!
This is the basic recipe; I've changed it around a lot depending on what I have... maple syrup for Karo, oat milk or almond milk for soymilk, other sugars for brown sugar, different nuts instead of sunflower seeds, a handful of dried fruit thrown it... whatever! It always seems to work, as long as the proportions stay fairly constant... so feel free to experiment!
Source of recipe: I came up with this recipe over time, as part of my continued efforts to sneak nutrition into my child's body. It could also be called, 'Not Too Junky After-School Snack'... good for camping & road-trip munchies, too.