Preheat oven to 350°F. Line one or two baking sheets with parchment paper and set aside.
In a large bowl, cream together 1/4 cup smooth peanut butter, 1/4 cup coconut oil (or softened butter), 6 tablespoons brown sugar, and 1/4 cup granulated sugar until smooth and combined.
Add 1 egg and 1/2 teaspoon vanilla extract (or 1/4 teaspoon vanilla bean paste). Beat or whip until the mixture is lighter in color and slightly fluffy, about 2 minutes.
Stir in 1/4 teaspoon baking soda and 1/2 teaspoon salt.
Add 1/2 cup all-purpose flour plus 1 tablespoon, and 1 cup quick-cooking oats. Mix slowly until just combined.
Fold in 3/4 cup baking chips and 1/3 cup Rice Krispies cereal by hand. Keep the 18 snack-size unwrapped Snickers bars separate for assembling.
Use a cookie scoop or spoon to divide the dough into 18 equal portions. For each portion: flatten the dough into a disk, place one Snickers in the center, fold the dough up around the candy and pinch to seal completely, then gently flatten the sealed ball into a cookie shape. Place each assembled cookie on the prepared baking sheet, spacing about 2 inches apart.
Bake 9–11 minutes, or until the bottoms start to turn light golden brown.
Cool the cookies on the baking sheet 3–5 minutes, then transfer to a cooling rack to finish cooling. Serve warm if desired.