Pre heat your oven to 400 degrees Fahrenheit. Make the walnut filling by adding toasted walnuts, maple syrup, and cinnamon to a food processor or blender. Blend on high for a minute or until a paste forms.
Core and thinly slice the apples and set them aside for later. Unfold and place your defrosted puff pastry flour side down. Gently roll it out with a rolling pin to flatten. Leaving a space in the middle use a sharp knife or pizza cutter to make diagonal cuts about an inch apart, on both sides of the pastry.
Spread an even layer of apple butter in the middle uncut section. Then add a layer of your maple walnut paste on top. Add an even layer of your sliced apples. Top the apples with a drizzle of maple syrup, a sprinkle of cinnamon and a pinch of nutmeg.
After folding the end in, start crossing over each section do this one at time and alternate every other. When you get to the last few pieces fold in the other end and tuck underneath the last few strands.
Mix 1 egg and a splash of water. Lightly brush the top of your braid with the egg wash and sprinkle with sugar if desired. Bake for 20 minutes and allow to cool for at least 5 minutes before cutting into. Enjoy!