1. Preheat your oven to 180°C (350°F).
2. In a bowl, combine 2 cups of rolled oats, 60g of oat flour, 1 teaspoon of cinnamon, and 1 teaspoon of baking powder. Mix well.
3. In another bowl, whisk together ½ cup of applesauce, ¼ cup of peanut butter, and ¼ cup of maple syrup until smooth. Grate one large apple using the largest hole of a box or cheese grater.
4. Pour the wet ingredients into the bowl with the dry ingredients, along with the grated apple. Stir until fully combined.
5. Line a loaf pan with parchment paper. Press the mixture evenly into the pan using a spatula to smooth the top.
6. Bake in the preheated oven for about 20 minutes, or until the edges are golden brown.
7. Allow the bars to cool completely in the pan.

Notes:
– For best flavour, use all-natural peanut butter with peanuts listed as the only ingredient. Drizzling the bars with peanut butter adds extra flavour.
– Opt for naturally sweet apples like Honeycrisp or Fuji for the best taste and sweetness.
– If you don’t have a loaf pan, an 8 by 8 brownie pan can be used for thinner bars. Alternatively, silicone mini bar molds work well too.
– If you don’t have oat flour, you can blend rolled oats into a flour-like consistency for similar results.

Ingredient Substitutions:
– Peanut Butter: Substitute with any nut butter, seed-based butter, or granola butter.
– Maple Syrup: Replace with honey if serving to children over 1 year old. If you prefer no sweetener, omit the maple syrup but add 1 to 2 tablespoons of extra applesauce to maintain moisture.

Storage Instructions:
– Once cooled, slice the bars and store them in an airtight container at room temperature for up to 4-5 days. For longer storage, freeze in a freezer-safe ziplock bag for up to 3 months before slicing into bars.