In a medium bowl, combine the oats, flour, baking powder, baking soda, and salt and mix well. Set aside.
In a large bowl or KitchenAid mixer, cream your butter, both sugars, egg, peanut butter, honey and vanilla.
Now take your dry oat mixture and pour it into your peanut butter mixture until just combined.
Drop in a rounded teaspoonful on an ungreased cookie sheet. Make sure to leave some space in between cookies because you now need to flatten the dough into a disk shape. You can use either just your fingers or I used the bottom of a glass. Just evenly press the bottom of a glass on top of your rounded cookie dough.
Bake for 8-10 minutes or until cookie is lightly browned. Let cool.
Creme Filling:
Blend together the 1 cup peanut butter and ½ cup powdered sugar for about 5 minutes.
Place half of your cookies upside down and drop about a tablespoon of filling in the middle. Then place another cookie on top and press evenly until the filling spreads just to the edges.
The Nutella also makes a great filling!
Recipe by Mandy's Recipe Box at https://mandysrecipeboxblog.com/peanut-butter-oatmeal-sandwich-cookies/