Line an 8×8 inch baking pan with parchment paper, leaving some overhang on the sides for easy removal later.
In a dry skillet over medium heat, toast the oats, almonds, and pumpkin seeds for 5-7 minutes, stirring frequently until they release a nutty aroma.
In a large bowl, mix together the toasted oats, nuts, seeds, dried apple pieces, cinnamon, nutmeg, and salt.
In a small saucepan over low heat, combine the almond butter, maple syrup, and coconut oil. Warm gently while stirring until completely smooth and integrated—about 3 minutes. Remove from heat and stir in the vanilla extract.
Pour the warm almond butter mixture over the dry ingredients and stir thoroughly until everything is well coated. If using chocolate chips, add them now.
Transfer the mixture to your prepared pan and press down firmly using the back of a measuring cup or your hands. Apply significant pressure to ensure the bars will hold together after setting.
Cover the pan with plastic wrap and refrigerate for at least 2 hours or overnight.
Once set, lift the entire slab out of the pan using the parchment paper overhang. With a sharp knife, cut into 12-16 bars depending on your preferred size. For the cleanest cuts, wipe the knife between slices.