Preheat oven to 350°F (175°C). Line baking pan with parchment paper.
In a saucepan, melt butter (or coconut oil) over medium heat. Stir in applesauce, maple syrup, brown sugar, vanilla, cinnamon, nutmeg, and salt. Heat until just bubbling, then remove from heat.
In a large bowl, combine oats, puffed rice, dried apples, and nuts (if using).
Pour warm mixture over dry ingredients. Stir until evenly coated. Fold in chocolate chips or raisins if desired.
Press mixture firmly into prepared pan using a spatula or damp hands.
Bake for 20–25 minutes until edges are golden and center is set.
Cool completely in pan before slicing into bars.