Preheat oven to 350 degrees. Line a baking sheet with parchment paper.
In a medium bowl, combine the brown sugar and peanut butter until they’re happy and fluffy. An electric mixer will probably work best for this step.
Add the egg and beat until combined.
Then mix in your oats, baking soda, and cinnamon until everything is cohesive (be one with the cookie dough).
Drop tablespoonfuls of dough onto the baking sheet, about 2 inches apart.
Now take the cookie sheet and place it in the refrigerator for 10-20 minutes. This well help the cookies from spreading out too much when they cook.
Bake for 11 minutes, or until they just barely start to brown on top. It’s okay if they look a little under-cooked, they’ll firm up. This is IMPORTANT. Do not overcook them or they will become crispy and suck. And then you’ll be sad.
Let the cookies cool for a few minutes, then transfer them onto a wire rack to cool completely.
Now, use a knife and spread a generous glop of jelly onto the flat part of one cookie. Then put another cookie on top of it. Congrats my friend, you just made a sammich!
Repeat this step until you have 8 adorable handheld bites of joy. They taste even better with a glass of milk :)