Preheat Oven : Set oven to 350°F (175°C). Line an 8x8-inch baking pan with parchment paper for easy removal.
Mix Dry Ingredients : In a large bowl, combine oats, chopped nuts, seeds, pumpkin pie spice, and salt. Mix well.
Prepare Wet Ingredients : In a small saucepan over low heat, combine pumpkin puree, honey (or maple syrup), and almond butter. Stir continuously until smooth and slightly warmed. Remove from heat and stir in vanilla extract.
Combine Mixtures : Pour the wet mixture over the dry ingredients. Stir well until every oat and nut is coated. Add optional chocolate chips or dried cranberries at this stage.
Press into Pan : Transfer the mixture to the prepared baking pan. Use a spatula or the back of a spoon to press it firmly and evenly.
Bake : Place in the oven and bake for 20–25 minutes, until edges turn golden brown.
Cool Completely : Remove from oven and let the granola bars cool in the pan. Once cooled, lift from the pan using the parchment paper and cut into 12 bars.