Grind your oats into fine pieces.
Cut your apples in half and hollow out center with seeds. Leave skin on (if using non-organic apples, you can de-skin apples also if you choose).
Add peanut butter to apple hollowed center. Set apples aside.
Make the pastry dough apple bases. In a bowl, add the flour and oats, butter, cinnamon, and then add water and honey, and cinnamon (if using). Fully combine with a spoon. You can use a little more water as needed to help the dough crumbly pieces stick together. The dough should stick together and have some crumbly bits.
Divide pastry dough into 3 equal balls. Flatten each with palm of hand and shape into circle or apple disc-base shapes that your apple halves will fit onto of.
When you're happy with your pastry discs, add a honey circle ring drizzle around to "glue" your apples to the pastry. The peanut butter will ooze out of the apples.
Bake at 325°F for about 25 minutes or until the pastry is lightly browned on the sides and bottom. You can leave in the oven after the temp is turned off for a softer baked apple tart.