In a large bowl, cream butter and sugars until well combined. Add eggs and vanilla mixing until well combined. Slowly add flour, pudding mix, baking soda and salt. Stir gently to combine. Stir in M and M's, butterfinger pieces, marshmallow bits, peanuts and pretzels. Stir to combine then transfer to baking dish pressing evenly. Bake for 35 minutes or until golden and baked through. Let cool completely then cut into squares and serve.