Starting out, preheat oven to 350ºF.
In a large mixing bowl, add your cake mix and peanut butter, mixing until crumbly.
Melt butter in microwave safe dish. Mix in milk, butter and eggs until completely incorporated (batter will be chunky).
Next, pour the batter into a lightly greased 9x13 cake pan and bake for 30-40 minutes or until a toothpick comes out clean.
Let the cake cool on the counter for 15 minutes.
Using a rounded kitchen utensil, poke holes across the top of the cake.
In a microwave safe bowl, add a cup of jelly and microwave in 30 second intervals until runny (stirring after each 30 second interval) then pour evenly over the top of the cake.
Next, place the cake in the fridge for 2 hours to cool completely.
Once chilled, spread on whipped topping and microwave remaining jelly and peanut butter to pour over the top (optional: mix peanut butter with whip topping before spreading).
Garnish with chopped peanuts if desired and serve.