Preheat oven to 350; smoosh 1.5 squares of break-apart refrigerated cookie dough into the bottom of each well. Place Reese cup upside down on top of cookie dough (or an Oreo!). Top with prepared box brownie mix, filling 3/4 full. Bake for 18 minutes! HEAVEN.
The glass jar look: This one is super easy — just fill with pine cones, beaded necklaces, and ornaments. And, if you don't have enough to fill it, check out Dandelions & Dust Bunnies' brilliant idea for beefing it up with a hidden toilet paper roll.